net/9p: switch to copy_from_iter_full()

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

net/9p/client.c

@@ -592,9 +592,8 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 		ename = &req->rc->sdata[req->rc->offset];
 		if (len > inline_len) {
 			/* We have error in external buffer */
-			err = copy_from_iter(ename + inline_len,
-					     len - inline_len, uidata);
-			if (err != len - inline_len) {
+			if (!copy_from_iter_full(ename + inline_len,
+					     len - inline_len, uidata)) {
 				err = -EFAULT;
 				goto out_err;
 			}

net/9p/protocol.c

@@ -74,7 +74,7 @@ pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size)
 {
 	size_t len = min(pdu->capacity - pdu->size, size);
 	struct iov_iter i = *from;
-	if (copy_from_iter(&pdu->sdata[pdu->size], len, &i) != len)
+	if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
 		len = 0;
 
 	pdu->size += len;