nfsd4: read encoding cleanup

Trivial cleanup, no change in functionality.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index bad762b..addb93b 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3075,6 +3075,7 @@
 				struct file *file, unsigned long maxcount)
 {
 	struct xdr_stream *xdr = &resp->xdr;
+	struct xdr_buf *buf = xdr->buf;
 	u32 eof;
 	int starting_len = xdr->buf->len - 8;
 	int space_left;
@@ -3097,7 +3098,7 @@
 		 * page length; reset it so as not to confuse
 		 * xdr_truncate_encode:
 		 */
-		xdr->buf->page_len = 0;
+		buf->page_len = 0;
 		return nfserr;
 	}
 
@@ -3105,29 +3106,29 @@
 	       read->rd_fhp->fh_dentry->d_inode->i_size);
 
 	tmp = htonl(eof);
-	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
+	write_bytes_to_xdr_buf(buf, starting_len    , &tmp, 4);
 	tmp = htonl(maxcount);
-	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
+	write_bytes_to_xdr_buf(buf, starting_len + 4, &tmp, 4);
 
-	resp->xdr.buf->page_len = maxcount;
-	xdr->buf->len += maxcount;
+	buf->page_len = maxcount;
+	buf->len += maxcount;
 	xdr->page_ptr += (maxcount + PAGE_SIZE - 1) / PAGE_SIZE;
-	xdr->iov = xdr->buf->tail;
+	xdr->iov = buf->tail;
 
 	/* Use rest of head for padding and remaining ops: */
-	resp->xdr.buf->tail[0].iov_base = xdr->p;
-	resp->xdr.buf->tail[0].iov_len = 0;
+	buf->tail[0].iov_base = xdr->p;
+	buf->tail[0].iov_len = 0;
 	if (maxcount&3) {
 		p = xdr_reserve_space(xdr, 4);
 		WRITE32(0);
-		resp->xdr.buf->tail[0].iov_base += maxcount&3;
-		resp->xdr.buf->tail[0].iov_len = 4 - (maxcount&3);
-		xdr->buf->len -= (maxcount&3);
+		buf->tail[0].iov_base += maxcount&3;
+		buf->tail[0].iov_len = 4 - (maxcount&3);
+		buf->len -= (maxcount&3);
 	}
 
 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
-				xdr->buf->buflen - xdr->buf->len);
-	xdr->buf->buflen = xdr->buf->len + space_left;
+				buf->buflen - buf->len);
+	buf->buflen = buf->len + space_left;
 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
 
 	return 0;