6lowpan: remove skb_deliver from IPHC

Separating skb delivery from decompression ensures that we can support further
decompression schemes and removes the mixed return value of error codes with
NET_RX_FOO.

Signed-off-by: Martin Townsend <mtownsend1973@gmail.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index d184df1..abfa359 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -372,12 +372,10 @@
 	return skb->len + uncomp_header - ret;
 }
 
-typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
-
 int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
 		const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
 		const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
-		u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
+		u8 iphc0, u8 iphc1);
 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 			unsigned short type, const void *_daddr,
 			const void *_saddr, unsigned int len);