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

[green@linuxhacker.ru]

From: Oleg Drokin <green@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@linuxhacker.ru>
CC: Daniel Vetter <daniel.vetter@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