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, 1 deletions

diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c
index 51c8240a1672..c5038e6447bd 100644
--- a/drivers/nfc/nfcmrvl/main.c
+++ b/drivers/nfc/nfcmrvl/main.c
@@ -68,7 +68,7 @@ static int nfcmrvl_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
 		unsigned char *hdr;
 		unsigned char len = skb->len;
 
-		hdr = (char *) skb_push(skb, NFCMRVL_HCI_EVENT_HEADER_SIZE);
+		hdr = skb_push(skb, NFCMRVL_HCI_EVENT_HEADER_SIZE);
 		hdr[0] = NFCMRVL_HCI_COMMAND_CODE;
 		hdr[1] = NFCMRVL_HCI_OGF;
 		hdr[2] = NFCMRVL_HCI_OCF;