rcu: Fix dubious "if" condition in __call_rcu_nocb_enqueue()

This commit replaces an incorrect (but fortunately functional)
bitwise OR ("|") operator with the correct logical OR ("||").
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcutree_plugin.h

@@ -2108,7 +2108,7 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
 
 	/* If we are not being polled and there is a kthread, awaken it ... */
 	t = ACCESS_ONCE(rdp->nocb_kthread);
-	if (rcu_nocb_poll | !t)
+	if (rcu_nocb_poll || !t)
 		return;
 	len = atomic_long_read(&rdp->nocb_q_count);
 	if (old_rhpp == &rdp->nocb_head) {