pNFS: Ensure nfs4_layoutget_prepare returns the correct error

If we're unable to perform the layoutget due to an invalid open stateid
or a bulk recall, ensure that we return the error so that the caller
can decide on an appropriate action.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -7760,6 +7760,7 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata)
 	struct nfs4_layoutget *lgp = calldata;
 	struct nfs_server *server = NFS_SERVER(lgp->args.inode);
 	struct nfs4_session *session = nfs4_get_session(server);
+	int ret;
 
 	dprintk("--> %s\n", __func__);
 	/* Note the is a race here, where a CB_LAYOUTRECALL can come in
@@ -7770,12 +7771,12 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata)
 	if (nfs41_setup_sequence(session, &lgp->args.seq_args,
 				&lgp->res.seq_res, task))
 		return;
-	if (pnfs_choose_layoutget_stateid(&lgp->args.stateid,
+	ret = pnfs_choose_layoutget_stateid(&lgp->args.stateid,
 					  NFS_I(lgp->args.inode)->layout,
 					  &lgp->args.range,
-					  lgp->args.ctx->state)) {
-		rpc_exit(task, NFS4_OK);
-	}
+					  lgp->args.ctx->state);
+	if (ret < 0)
+		rpc_exit(task, ret);
 }
 
 static void nfs4_layoutget_done(struct rpc_task *task, void *calldata)