SUNRPC: Split out xdr_realign_pages() from xdr_align_pages()

I don't need the entire align pages code for READ_PLUS, so split out the
part I do need so I don't need to reimplement anything.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xdr.c

@@ -997,26 +997,33 @@ __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
 }
 EXPORT_SYMBOL_GPL(xdr_inline_decode);
 
-static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
+static void xdr_realign_pages(struct xdr_stream *xdr)
 {
 	struct xdr_buf *buf = xdr->buf;
-	struct kvec *iov;
-	unsigned int nwords = XDR_QUADLEN(len);
+	struct kvec *iov = buf->head;
 	unsigned int cur = xdr_stream_pos(xdr);
 	unsigned int copied, offset;
 
-	if (xdr->nwords == 0)
-		return 0;
-
 	/* Realign pages to current pointer position */
-	iov = buf->head;
 	if (iov->iov_len > cur) {
 		offset = iov->iov_len - cur;
 		copied = xdr_shrink_bufhead(buf, offset);
 		trace_rpc_xdr_alignment(xdr, offset, copied);
 		xdr->nwords = XDR_QUADLEN(buf->len - cur);
 	}
+}
+
+static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
+{
+	struct xdr_buf *buf = xdr->buf;
+	unsigned int nwords = XDR_QUADLEN(len);
+	unsigned int cur = xdr_stream_pos(xdr);
+	unsigned int copied, offset;
+
+	if (xdr->nwords == 0)
+		return 0;
 
+	xdr_realign_pages(xdr);
 	if (nwords > xdr->nwords) {
 		nwords = xdr->nwords;
 		len = nwords << 2;