[PATCH v2 3/2] lib/uuid.c: Silence an unchecked return value warning

["George Spelvin" <linux@sciencehorizons.net>]

Andy Shevchenko pointed out that __uuid_to_bin doesn't need to check
the return value from hex2bin(), because the preceding uuid_is_valid()
check already took care of that.

But hex2bin() is declared __must_check, so checking anyway is the
simplest way to silence the warning.

This cancels a small fraction of the the space savings, but not all:

	vs. previous patch		vs. before patch series
	Before  After   Delta   Percent	Orig.	Delta Percent
x86-32	90	 96	 +6	6.7%	122	-26	-21.3%
x86-64	90	 96	 +6	6.7%	127     -31	-24.4%
arm	92	104	+12	13.0%	116     -12	-10.3%
thumb	50	 62	+12	24.0%	100     -38	-38.0%
arm64	116	124	 +8	6.9%	148     -24	-16.2%

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
---
 lib/uuid.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/uuid.c b/lib/uuid.c
index 93945915..1a6dbbd2 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -104,7 +104,8 @@ static int __uuid_to_bin(const char uuid[36], __u8 b[16], const u8 pos[16])
 		return -EINVAL;
 
 	for (i = 0; i < 16; i++)
-		hex2bin(b + i, uuid + pos[i], 1);
+		if (hex2bin(b + i, uuid + pos[i], 1) < 0)
+			return -EINVAL;
 
 	return 0;
 }
-- 
2.8.1