SUNRPC: Fix corruption of xdr->nwords in xdr_copy_to_scratch

When we copy the first part of the data, we need to ensure that value
of xdr->nwords is updated as well. Do so by calling __xdr_inline_decode()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xdr.c

@@ -859,12 +859,15 @@ EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer);
 static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
 {
 	__be32 *p;
-	void *cpdest = xdr->scratch.iov_base;
+	char *cpdest = xdr->scratch.iov_base;
 	size_t cplen = (char *)xdr->end - (char *)xdr->p;
 
 	if (nbytes > xdr->scratch.iov_len)
 		return NULL;
-	memcpy(cpdest, xdr->p, cplen);
+	p = __xdr_inline_decode(xdr, cplen);
+	if (p == NULL)
+		return NULL;
+	memcpy(cpdest, p, cplen);
 	cpdest += cplen;
 	nbytes -= cplen;
 	if (!xdr_set_next_buffer(xdr))