locking/lockdep: Remove unnecessary DEBUG_LOCKS_WARN_ON()

DEBUG_LOCKS_WARN_ON() will turn off debug_locks and
makes print_unlock_imbalance_bug() return directly.

Remove a redundant whitespace.

Signed-off-by: Kobe Wu <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: <[e-mail]>
Cc: <[e-mail]>
Cc: Eason Lin <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Will Deacon <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

kernel/locking/lockdep.c

···
 	 * So we're all set to release this lock.. wait what lock? We don't
 	 * own any locks, you've been drinking again?
 	 */
-	if (DEBUG_LOCKS_WARN_ON(depth <= 0)) {
+	if (depth <= 0) {
 		print_unlock_imbalance_bug(curr, lock, ip);
 		return 0;
 	}