[PATCH] drm/omap: dsi: fix unsigned expression compared with zero

[angkery <angkery@163.com>]

From: Junlin Yang <yangjunlin@yulong.com>

r is "u32" always >= 0,mipi_dsi_create_packet may return little than zero.
so r < 0 condition is never accessible.

Fixes coccicheck warnings:
./drivers/gpu/drm/omapdrm/dss/dsi.c:2155:5-6:
WARNING: Unsigned expression compared with zero: r < 0

Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
---
 drivers/gpu/drm/omapdrm/dss/dsi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index 8e11612..b31d750 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -2149,11 +2149,12 @@ static int dsi_vc_send_short(struct dsi_data *dsi, int vc,
 			     const struct mipi_dsi_msg *msg)
 {
 	struct mipi_dsi_packet pkt;
+	int ret;
 	u32 r;
 
-	r = mipi_dsi_create_packet(&pkt, msg);
-	if (r < 0)
-		return r;
+	ret = mipi_dsi_create_packet(&pkt, msg);
+	if (ret < 0)
+		return ret;
 
 	WARN_ON(!dsi_bus_is_locked(dsi));
 
-- 
1.9.1