[PATCH 4/5] drivers/acpi: elide a non-zero test on a result that is never 0

[Julia Lawall <julia@diku.dk>]

From: Julia Lawall <julia@diku.dk>

The function thermal_cooling_device_register always returns either a valid
pointer or a value made with ERR_PTR, so a test for non-zero on the result
will always succeed.


The problem was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)

//<smpl>
@a@
expression E, E1;
statement S,S1;
position p;
@@

E = thermal_cooling_device_register(...)
... when != E = E1
if@p (E) S else S1

@n@
position a.p;
expression E,E1;
statement S,S1;
@@

E = NULL
... when != E = E1
if@p (E) S else S1

@depends on !n@
expression E;
statement S,S1;
position a.p;
@@

* if@p (E)
  S else S1
//</smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
---
 drivers/acpi/fan.c            |   34 ++++++++++++++++------------------
 drivers/acpi/processor_core.c |   30 ++++++++++++++----------------
 drivers/acpi/video.c          |   28 +++++++++++++---------------
 3 files changed, 43 insertions(+), 49 deletions(-)

diff -u -p a/drivers/acpi/fan.c b/drivers/acpi/fan.c
--- a/drivers/acpi/fan.c	2008-03-12 14:13:13.000000000 +0100
+++ b/drivers/acpi/fan.c	2008-03-24 16:14:50.000000000 +0100
@@ -260,24 +260,22 @@ static int acpi_fan_add(struct acpi_devi
 		result = PTR_ERR(cdev);
 		goto end;
 	}
-	if (cdev) {
-		printk(KERN_INFO PREFIX
-			"%s is registered as cooling_device%d\n",
-			device->dev.bus_id, cdev->id);
-
-		acpi_driver_data(device) = cdev;
-		result = sysfs_create_link(&device->dev.kobj,
-					   &cdev->device.kobj,
-					   "thermal_cooling");
-		if (result)
-			return result;
-
-		result = sysfs_create_link(&cdev->device.kobj,
-					   &device->dev.kobj,
-					   "device");
-		if (result)
-			return result;
-	}
+	printk(KERN_INFO PREFIX
+		"%s is registered as cooling_device%d\n",
+		device->dev.bus_id, cdev->id);
+
+	acpi_driver_data(device) = cdev;
+	result = sysfs_create_link(&device->dev.kobj,
+				   &cdev->device.kobj,
+				   "thermal_cooling");
+	if (result)
+		return result;
+
+	result = sysfs_create_link(&cdev->device.kobj,
+				   &device->dev.kobj,
+				   "device");
+	if (result)
+		return result;
 
 	result = acpi_fan_add_fs(device);
 	if (result)
diff -u -p a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
--- a/drivers/acpi/processor_core.c	2008-03-12 14:13:13.000000000 +0100
+++ b/drivers/acpi/processor_core.c	2008-03-24 16:15:53.000000000 +0100
@@ -674,22 +674,20 @@ static int __cpuinit acpi_processor_star
 		result = PTR_ERR(pr->cdev);
 		goto end;
 	}
-	if (pr->cdev) {
-		printk(KERN_INFO PREFIX
-			"%s is registered as cooling_device%d\n",
-			device->dev.bus_id, pr->cdev->id);
-
-		result = sysfs_create_link(&device->dev.kobj,
-					   &pr->cdev->device.kobj,
-					   "thermal_cooling");
-		if (result)
-			return result;
-		result = sysfs_create_link(&pr->cdev->device.kobj,
-					   &device->dev.kobj,
-					   "device");
-		if (result)
-			return result;
-	}
+	printk(KERN_INFO PREFIX
+		"%s is registered as cooling_device%d\n",
+		device->dev.bus_id, pr->cdev->id);
+
+	result = sysfs_create_link(&device->dev.kobj,
+				   &pr->cdev->device.kobj,
+				   "thermal_cooling");
+	if (result)
+		return result;
+	result = sysfs_create_link(&pr->cdev->device.kobj,
+				   &device->dev.kobj,
+				   "device");
+	if (result)
+		return result;
 
 	if (pr->flags.throttling) {
 		printk(KERN_INFO PREFIX "%s [%s] (supports",
diff -u -p a/drivers/acpi/video.c b/drivers/acpi/video.c
--- a/drivers/acpi/video.c	2008-03-12 14:13:13.000000000 +0100
+++ b/drivers/acpi/video.c	2008-03-24 16:17:17.000000000 +0100
@@ -734,21 +734,19 @@ static void acpi_video_device_find_cap(s
 		if (IS_ERR(device->cdev))
 			return;
 
-		if (device->cdev) {
-			printk(KERN_INFO PREFIX
-				"%s is registered as cooling_device%d\n",
-				device->dev->dev.bus_id, device->cdev->id);
-			result = sysfs_create_link(&device->dev->dev.kobj,
-					  &device->cdev->device.kobj,
-					  "thermal_cooling");
-			if (result)
-				printk(KERN_ERR PREFIX "Create sysfs link\n");
-			result = sysfs_create_link(&device->cdev->device.kobj,
-					  &device->dev->dev.kobj,
-					  "device");
-                        if (result)
-				printk(KERN_ERR PREFIX "Create sysfs link\n");
-		}
+		printk(KERN_INFO PREFIX
+			"%s is registered as cooling_device%d\n",
+			device->dev->dev.bus_id, device->cdev->id);
+		result = sysfs_create_link(&device->dev->dev.kobj,
+				  &device->cdev->device.kobj,
+				  "thermal_cooling");
+		if (result)
+			printk(KERN_ERR PREFIX "Create sysfs link\n");
+		result = sysfs_create_link(&device->cdev->device.kobj,
+				  &device->dev->dev.kobj,
+				  "device");
+		if (result)
+			printk(KERN_ERR PREFIX "Create sysfs link\n");
 	}
 	if (device->cap._DCS && device->cap._DSS){
 		static int count = 0;