[PATCH 2/2] drm: fix a memleak on mutex failure path

[green at linuxhacker.ru]

From: Oleg Drokin <green at linuxhacker.ru>

Need to free just allocated ctx allocation if we cannot
get our config mutex.

This one has been flagged by kbuild bot all the way back in August,
but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html

Found with smatch.

Signed-off-by: Oleg Drokin <green at linuxhacker.ru>
CC: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_modeset_lock.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
index 51cc47d..1e8c52f 100644
--- a/drivers/gpu/drm/drm_modeset_lock.c
+++ b/drivers/gpu/drm/drm_modeset_lock.c
@@ -80,8 +80,10 @@ int __drm_modeset_lock_all(struct drm_device *dev,
 		return -ENOMEM;
 
 	if (trylock) {
-		if (!mutex_trylock(&config->mutex))
+		if (!mutex_trylock(&config->mutex)) {
+			kfree(ctx);
 			return -EBUSY;
+		}
 	} else {
 		mutex_lock(&config->mutex);
 	}
-- 
2.1.0