SUNRPC: Clean up xdr_enter_page

Use the xdr_align_pages() helper
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xdr.c

@@ -826,13 +826,13 @@ EXPORT_SYMBOL_GPL(xdr_read_pages);
  */
 void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
 {
-	len = xdr_read_pages(xdr, len);
+	len = xdr_align_pages(xdr, len);
 	/*
 	 * Position current pointer at beginning of tail, and
 	 * set remaining message length.
 	 */
-	xdr_set_page_base(xdr, 0, len);
-	xdr->nwords += XDR_QUADLEN(xdr->buf->page_len);
+	if (len != 0)
+		xdr_set_page_base(xdr, 0, len);
 }
 EXPORT_SYMBOL_GPL(xdr_enter_page);