networking: make skb_put & friends 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 (skb_put, __skb_put and pskb_put) 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_put, __skb_put };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_put, __skb_put };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

which actually doesn't cover pskb_put since there are only three
users overall.

A handful of stragglers were converted manually, notably a macro in
drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many
instances in net/bluetooth/hci_sock.c. In the former file, I also
had to fix one whitespace problem spatch introduced.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 1d6e180..7418088 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -650,7 +650,7 @@ static void hwsim_send_ps_poll(void *dat, u8 *mac, struct ieee80211_vif *vif)
 	skb = dev_alloc_skb(sizeof(*pspoll));
 	if (!skb)
 		return;
-	pspoll = (void *) skb_put(skb, sizeof(*pspoll));
+	pspoll = skb_put(skb, sizeof(*pspoll));
 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 					    IEEE80211_STYPE_PSPOLL |
 					    IEEE80211_FCTL_PM);
@@ -681,7 +681,7 @@ static void hwsim_send_nullfunc(struct mac80211_hwsim_data *data, u8 *mac,
 	skb = dev_alloc_skb(sizeof(*hdr));
 	if (!skb)
 		return;
-	hdr = (void *) skb_put(skb, sizeof(*hdr) - ETH_ALEN);
+	hdr = skb_put(skb, sizeof(*hdr) - ETH_ALEN);
 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
 					 IEEE80211_STYPE_NULLFUNC |
 					 (ps ? IEEE80211_FCTL_PM : 0));
@@ -892,7 +892,7 @@ static void mac80211_hwsim_monitor_ack(struct ieee80211_channel *chan,
 	if (skb == NULL)
 		return;
 
-	hdr = (struct hwsim_radiotap_ack_hdr *) skb_put(skb, sizeof(*hdr));
+	hdr = skb_put(skb, sizeof(*hdr));
 	hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION;
 	hdr->hdr.it_pad = 0;
 	hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
@@ -904,7 +904,7 @@ static void mac80211_hwsim_monitor_ack(struct ieee80211_channel *chan,
 	flags = IEEE80211_CHAN_2GHZ;
 	hdr->rt_chbitmask = cpu_to_le16(flags);
 
-	hdr11 = (struct ieee80211_hdr *) skb_put(skb, 10);
+	hdr11 = skb_put(skb, 10);
 	hdr11->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 					   IEEE80211_STYPE_ACK);
 	hdr11->duration_id = cpu_to_le16(0);