idr: reduce the unneeded check in free_layer()

If "idr->hint == p" is true, it also implies "idr->hint" is true(not NULL).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/idr.c

@@ -145,7 +145,7 @@ static void idr_layer_rcu_free(struct rcu_head *head)
 
 static inline void free_layer(struct idr *idr, struct idr_layer *p)
 {
-	if (idr->hint && idr->hint == p)
+	if (idr->hint == p)
 		RCU_INIT_POINTER(idr->hint, NULL);
 	call_rcu(&p->rcu_head, idr_layer_rcu_free);
 }