netmgr: Always load the result from async socket

Because we use result earlier for setting the loadbalancing on the
socket, we could be left with a ISC_R_NOTIMPLEMENTED value stored in the
variable and when the UDP connection would succeed, we would
errorneously return this value instead of ISC_R_SUCCESS.

lib/isc/netmgr/udp.c

@@ -841,9 +841,7 @@ isc_nm_udpconnect(isc_nm_t *mgr, isc_nmiface_t *local, isc_nmiface_t *peer,
 		isc__nm_uvreq_put(&req, sock);
 	}
 
-	if (atomic_load(&sock->result) != ISC_R_SUCCESS) {
-		result = atomic_load(&sock->result);
-	}
+	result = atomic_load(&sock->result);
 
 	isc__nmsocket_detach(&tmp);