slirp: replace error_report() with g_critical()

Reduce dependency on QEMU. QEMU could use a custom log handler if it
wants to redirect/filter it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

slirp/misc.c

@@ -162,7 +162,7 @@ fork_exec(struct socket *so, const char *ex)
     g_strfreev(argv);
 
     if (err) {
-        error_report("%s", err->message);
+        g_critical("fork_exec: %s", err->message);
         g_error_free(err);
         closesocket(sp[0]);
         closesocket(sp[1]);