pxafb: convert ctrlr_sem in a mutex

The semaphore ctrlr_sem is used as a mutex.  Convert it to the mutex API.

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/pxafb.h b/drivers/video/pxafb.h
index 8238dc8..31541b8 100644
--- a/drivers/video/pxafb.h
+++ b/drivers/video/pxafb.h
@@ -106,7 +106,7 @@
 
 	volatile u_char		state;
 	volatile u_char		task_state;
-	struct semaphore	ctrlr_sem;
+	struct mutex		ctrlr_lock;
 	wait_queue_head_t	ctrlr_wait;
 	struct work_struct	task;