RDMA/nes: Add missing rcu_read_unlock() in nes_addr_resolve_neigh()

Make sure all exit paths from this function unlock everything.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index 183f7ab..271279c 100644
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -1363,8 +1363,7 @@
 				if (!memcmp(nesadapter->arp_table[arpindex].mac_addr,
 					    neigh->ha, ETH_ALEN)) {
 					/* Mac address same as in nes_arp_table */
-					ip_rt_put(rt);
-					return rc;
+					goto out;
 				}
 
 				nes_manage_arp_cache(nesvnic->netdev,
@@ -1380,6 +1379,8 @@
 			neigh_event_send(neigh, NULL);
 		}
 	}
+
+out:
 	rcu_read_unlock();
 	ip_rt_put(rt);
 	return rc;