networking: make skb_push & __skb_push return void pointers

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 4 deletions

diff --git a/drivers/net/wireless/intersil/prism54/islpci_eth.c b/drivers/net/wireless/intersil/prism54/islpci_eth.c
index d83f6332019e..9b0ded733294 100644
--- a/drivers/net/wireless/intersil/prism54/islpci_eth.c
+++ b/drivers/net/wireless/intersil/prism54/islpci_eth.c
@@ -276,10 +276,7 @@ islpci_monitor_rx(islpci_private *priv, struct sk_buff **skb)
 		}
 
 		/* make room for the new header and fill it. */
-		avs =
-		    (struct avs_80211_1_header *) skb_push(*skb,
-							   sizeof (struct
-								   avs_80211_1_header));
+		avs = skb_push(*skb, sizeof(struct avs_80211_1_header));
 
 		avs->version = cpu_to_be32(P80211CAPTURE_VERSION);
 		avs->length = cpu_to_be32(sizeof (struct avs_80211_1_header));