tap: Finish conversion of tap_open() to Error

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1431691143-1015-15-git-send-email-armbru@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

net/tap.c

@@ -597,10 +597,6 @@ static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
     TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
                       mq_required, errp));
     if (fd < 0) {
-        /* FIXME drop when all tap_open() store an Error */
-        if (errp && !*errp) {
-            error_setg(errp, "can't open tap device");
-        }
         return -1;
     }