Check for negative wait time in socket_full.

util.c

@@ -1033,6 +1033,8 @@ static bool socket_full(struct pool *pool, int wait)
 	struct timeval timeout;
 	fd_set rd;
 
+	if (unlikely(wait < 0))
+		wait = 0;
 	FD_ZERO(&rd);
 	FD_SET(sock, &rd);
 	timeout.tv_usec = 0;