lockdep: Fix wait-type for empty stack

[ Upstream commit f8b298c ]

Even the very first lock can violate the wait-context check, consider
the various IRQ contexts.

Fixes: de8f5e4 ("lockdep: Introduce wait-type checks")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210617190313.256987481@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

kernel/locking/lockdep.c

@@ -4626,7 +4626,7 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
 	short curr_inner;
 	int depth;
 
-	if (!curr->lockdep_depth || !next_inner || next->trylock)
+	if (!next_inner || next->trylock)
 		return 0;
 
 	if (!next_outer)