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, 2 insertions, 4 deletions

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
index 35fe991dcc56..55198ac2b755 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
@@ -278,8 +278,7 @@ static void rtl8187_tx(struct ieee80211_hw *dev,
 	}
 
 	if (!priv->is_rtl8187b) {
-		struct rtl8187_tx_hdr *hdr =
-			(struct rtl8187_tx_hdr *)skb_push(skb, sizeof(*hdr));
+		struct rtl8187_tx_hdr *hdr = skb_push(skb, sizeof(*hdr));
 		hdr->flags = cpu_to_le32(flags);
 		hdr->len = 0;
 		hdr->rts_duration = rts_dur;
@@ -292,8 +291,7 @@ static void rtl8187_tx(struct ieee80211_hw *dev,
 		unsigned int epmap[4] = { 6, 7, 5, 4 };
 		u16 fc = le16_to_cpu(tx_hdr->frame_control);
 
-		struct rtl8187b_tx_hdr *hdr =
-			(struct rtl8187b_tx_hdr *)skb_push(skb, sizeof(*hdr));
+		struct rtl8187b_tx_hdr *hdr = skb_push(skb, sizeof(*hdr));
 		struct ieee80211_rate *txrate =
 			ieee80211_get_tx_rate(dev, info);
 		memset(hdr, 0, sizeof(*hdr));