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, 3 deletions

diff --git a/drivers/target/iscsi/cxgbit/cxgbit_target.c b/drivers/target/iscsi/cxgbit/cxgbit_target.c
index bdcc8b4c522a..dda13f1af38e 100644
--- a/drivers/target/iscsi/cxgbit/cxgbit_target.c
+++ b/drivers/target/iscsi/cxgbit/cxgbit_target.c
@@ -136,7 +136,7 @@ cxgbit_cpl_tx_data_iso(struct sk_buff *skb, struct cxgbit_iso_info *iso_info)
 	unsigned int fslice = !!(iso_info->flags & CXGBIT_ISO_FSLICE);
 	unsigned int lslice = !!(iso_info->flags & CXGBIT_ISO_LSLICE);
 
-	cpl = (struct cpl_tx_data_iso *)__skb_push(skb, sizeof(*cpl));
+	cpl = __skb_push(skb, sizeof(*cpl));
 
 	cpl->op_to_scsi = htonl(CPL_TX_DATA_ISO_OP_V(CPL_TX_DATA_ISO) |
 			CPL_TX_DATA_ISO_FIRST_V(fslice) |
@@ -183,8 +183,7 @@ cxgbit_tx_data_wr(struct cxgbit_sock *csk, struct sk_buff *skb, u32 dlen,
 	if (cxgbit_is_ofld_imm(skb))
 		immlen += dlen;
 
-	req = (struct fw_ofld_tx_data_wr *)__skb_push(skb,
-							hdr_size);
+	req = __skb_push(skb, hdr_size);
 	req->op_to_immdlen = cpu_to_be32(FW_WR_OP_V(opcode) |
 					FW_WR_COMPL_V(compl) |
 					FW_WR_IMMDLEN_V(immlen));