[AX25]: ax25_rt_add() locking fix.

Fix deadlock identified by the Stanford locking checker.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@redhat.com>

net/ax25/ax25_route.c

@@ -122,6 +122,7 @@ static int ax25_rt_add(struct ax25_routes_struct *route)
 					ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
 				}
 			}
+			write_unlock(&ax25_route_lock);
 			return 0;
 		}
 		ax25_rt = ax25_rt->next;