wxx: Fix broken TCP networking (regression)

It is broken since commit c619644.

Reported-by: Michael Fritscher <michael@fritscher.net>
Tested-by: Michael Fritscher <michael@fritscher.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>

slirp/slirp.h

@@ -347,9 +347,4 @@ struct tcpcb *tcp_drop(struct tcpcb *tp, int err);
 #define max(x,y) ((x) > (y) ? (x) : (y))
 #endif
 
-#ifdef _WIN32
-#undef errno
-#define errno (WSAGetLastError())
-#endif
-
 #endif

slirp/tcp_input.c

@@ -659,6 +659,7 @@ tcp_input(struct mbuf *m, int iphlen, struct socket *inso, unsigned short af)
 	  }
 
 	  if ((tcp_fconnect(so, so->so_ffamily) == -1) &&
+              (errno != EAGAIN) &&
               (errno != EINPROGRESS) && (errno != EWOULDBLOCK)
           ) {
 	    uint8_t code;