locking/lockdep: Remove redundant argument in check_deadlock

In check_deadlock(), the third argument read comes from the second
argument hlock so that it can be removed. No functional change.
Signed-off-by: NYuyang Du <duyuyang@gmail.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-18-duyuyang@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

kernel/locking/lockdep.c

@@ -2246,7 +2246,7 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
  * Returns: 0 on deadlock detected, 1 on OK, 2 on recursive read
  */
 static int
-check_deadlock(struct task_struct *curr, struct held_lock *next, int read)
+check_deadlock(struct task_struct *curr, struct held_lock *next)
 {
 	struct held_lock *prev;
 	struct held_lock *nest = NULL;
@@ -2265,7 +2265,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, int read)
 		 * Allow read-after-read recursion of the same
 		 * lock class (i.e. read_lock(lock)+read_lock(lock)):
 		 */
-		if ((read == 2) && prev->read)
+		if ((next->read == 2) && prev->read)
 			return 2;
 
 		/*
@@ -2839,7 +2839,7 @@ static int validate_chain(struct task_struct *curr,
 		 * The simple case: does the current hold the same lock
 		 * already?
 		 */
-		int ret = check_deadlock(curr, hlock, hlock->read);
+		int ret = check_deadlock(curr, hlock);
 
 		if (!ret)
 			return 0;