kvm tools: Fix crash when /etc/resolv.conf doesn't exist

In uip_dhcp_get_dns() we try to open /etc/resolv.conf. If we fail to
open it we then SEGV trying to fclose() it.

Fix the code to just return directly if we can't open it.

Acked-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

net/uip/dhcp.c

@@ -45,7 +45,7 @@ int uip_dhcp_get_dns(struct uip_info *info)
 
 	fp = fopen("/etc/resolv.conf", "r");
 	if (!fp)
-		goto out;
+		return ret;
 
 	while (!feof(fp)) {
 		if (fscanf(fp, "%s %s\n", key, val) != 2)
@@ -62,7 +62,6 @@ int uip_dhcp_get_dns(struct uip_info *info)
 		}
 	}
 
-out:
 	fclose(fp);
 	return ret;
 }