net: Remove useless function skb_header_release

There is no one which would invokes the function skb_header_release.
So just remove it now.
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/asix_common.c

@@ -245,7 +245,7 @@ struct sk_buff *asix_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
 	 * - We are allowed to put 4 bytes at tail if skb_cloned()
 	 *   is false (and if we have 4 bytes of tailroom)
 	 *
-	 * TCP packets for example are cloned, but skb_header_release()
+	 * TCP packets for example are cloned, but __skb_header_release()
 	 * was called in tcp stack, allowing us to use headroom for our needs.
 	 */
 	if (!skb_header_cloned(skb) &&

include/linux/skbuff.h

@@ -1456,28 +1456,9 @@ static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
 	return 0;
 }
 
-/**
- *	skb_header_release - release reference to header
- *	@skb: buffer to operate on
- *
- *	Drop a reference to the header part of the buffer.  This is done
- *	by acquiring a payload reference.  You must not read from the header
- *	part of skb->data after this.
- *	Note : Check if you can use __skb_header_release() instead.
- */
-static inline void skb_header_release(struct sk_buff *skb)
-{
-	BUG_ON(skb->nohdr);
-	skb->nohdr = 1;
-	atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
-}
-
 /**
  *	__skb_header_release - release reference to header
  *	@skb: buffer to operate on
- *
- *	Variant of skb_header_release() assuming skb is private to caller.
- *	We can avoid one atomic operation.
  */
 static inline void __skb_header_release(struct sk_buff *skb)
 {

net/batman-adv/soft-interface.c

@@ -69,7 +69,7 @@ int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
 	int result;
 
 	/* TODO: We must check if we can release all references to non-payload
-	 * data using skb_header_release in our skbs to allow skb_cow_header to
+	 * data using __skb_header_release in our skbs to allow skb_cow_header to
 	 * work optimally. This means that those skbs are not allowed to read
 	 * or write any data which is before the current position of skb->data
 	 * after that call and thus allow other skbs with the same data buffer