sunrpc: clean up xdr_shrink_pagelen use of temporary pointer

char *p is used only as a shorthand for tail->iov_base + len in a nested
block.  Move it there.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xdr.c

@@ -395,16 +395,15 @@ xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
 {
 	struct kvec *tail;
 	size_t copy;
-	char *p;
 	unsigned int pglen = buf->page_len;
 
 	tail = buf->tail;
 	BUG_ON (len > pglen);
 
 	/* Shift the tail first */
 	if (tail->iov_len != 0) {
-		p = (char *)tail->iov_base + len;
 		if (tail->iov_len > len) {
+			char *p = (char *)tail->iov_base + len;
 			copy = tail->iov_len - len;
 			memmove(p, tail->iov_base, copy);
 		}