ieee802154: cleanup WARN_ON for fc fetch

This patch cleanups the WARN_ON which occurs when the sk buffer has
insufficient buffer space by moving the WARN_ON into if condition.

Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/include/net/mac802154.h b/include/net/mac802154.h
index bb7bfecc5ab3..286824acd008 100644
--- a/include/net/mac802154.h
+++ b/include/net/mac802154.h
@@ -250,11 +250,10 @@ static inline __le16 ieee802154_get_fc_from_skb(const struct sk_buff *skb)
         __le16 fc;
 
         /* check if we can fc at skb_mac_header of sk buffer */
-        if (unlikely(!skb_mac_header_was_set(skb) ||
-                     (skb_tail_pointer(skb) - skb_mac_header(skb)) < 2)) {
-                WARN_ON(1);
+        if (WARN_ON(!skb_mac_header_was_set(skb) ||
+                    (skb_tail_pointer(skb) -
+                     skb_mac_header(skb)) < IEEE802154_FC_LEN))
                 return cpu_to_le16(0);
-        }
 
         memcpy(&fc, skb_mac_header(skb), IEEE802154_FC_LEN);
         return fc;