sys_net: add a workaround for WSAPoll with timeout

Don't call WSAPoll with empty socket list.

rpcs3/Emu/Cell/lv2/sys_net.cpp

@@ -83,7 +83,25 @@ void fmt_class_string<sys_net_error>::format(std::string& out, u64 arg)
 // Workaround function for WSAPoll not reporting failed connections
 void windows_poll(pollfd* fds, unsigned long nfds, int timeout, bool* connecting)
 {
+	// Don't call WSAPoll with zero nfds
+	if (nfds == 0)
+	{
+		if (timeout > 0)
+		{
+			Sleep(timeout);
+		}
+
+		return;
+	}
+
 	int r = ::WSAPoll(fds, nfds, timeout);
+
+	if (r == SOCKET_ERROR)
+	{
+		sys_net.error("WSAPoll failed: %u", WSAGetLastError());
+		return;
+	}
+
 	for (unsigned long i = 0; i < nfds; i++)
 	{
 		if (connecting[i])