AF_XDP-interaction: Fix another warning in complete_tx

warning: ‘return’ with no value, in function returning non-void

Signed-off-by: Jesper Dangaard Brouer <[email protected]>

Author: netoptimizer

AF_XDP-interaction/af_xdp_user.c

@@ -561,7 +561,7 @@ static int complete_tx(struct xsk_socket_info *xsk)
 	int err;
 
 	if (!xsk->outstanding_tx)
-		return;
+		return 0;
 
 	/* Notify kernel via sendto syscall that TX packet are avail */
 	err = kick_tx(xsk);