pnfs: fail comparison when bucket verifier not set

This skips the WARN_ON_ONCE, but doesnt change behavior (the memcmp would
fail).

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

fs/nfs/direct.c

@@ -222,7 +222,11 @@ static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
 
 	verfp = nfs_direct_select_verf(dreq, data->ds_clp,
 					 data->ds_commit_index);
-	WARN_ON_ONCE(verfp->committed < 0);
+
+	/* verifier not set so always fail */
+	if (verfp->committed < 0)
+		return 1;
+
 	return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf));
 }