mutex: remove unused field "name" in debug mode

This field is unused and uninitialized since commit 9a11b49a8056
("[PATCH] lockdep: better lock debugging")

Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mutex.h

@@ -59,7 +59,6 @@ struct mutex {
 	struct optimistic_spin_queue osq; /* Spinner MCS lock */
 #endif
 #ifdef CONFIG_DEBUG_MUTEXES
-	const char 		*name;
 	void			*magic;
 #endif
 #ifdef CONFIG_DEBUG_LOCK_ALLOC