ipv6: fix illegal mac_header comparison on 32bit

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 74db47e..ded45ec 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1741,6 +1741,11 @@
 }
 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
 
+static inline void skb_pop_mac_header(struct sk_buff *skb)
+{
+	skb->mac_header = skb->network_header;
+}
+
 static inline void skb_probe_transport_header(struct sk_buff *skb,
 					      const int offset_hint)
 {