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>
diff --git a/slirp/misc.c b/slirp/misc.c
index 753b3da..b141446 100644
--- a/slirp/misc.c
+++ b/slirp/misc.c
@@ -162,7 +162,7 @@
     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]);