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/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index 8e4154b..b23a0b0 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -293,7 +293,7 @@ static int create_qp(struct c4iw_rdev *rdev, struct t4_wq *wq,
 	}
 	set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
 
-	res_wr = (struct fw_ri_res_wr *)__skb_put(skb, wr_len);
+	res_wr = __skb_put(skb, wr_len);
 	memset(res_wr, 0, wr_len);
 	res_wr->op_nres = cpu_to_be32(
 			FW_WR_OP_V(FW_RI_RES_WR) |
@@ -1228,7 +1228,7 @@ static void post_terminate(struct c4iw_qp *qhp, struct t4_cqe *err_cqe,
 
 	set_wr_txq(skb, CPL_PRIORITY_DATA, qhp->ep->txq_idx);
 
-	wqe = (struct fw_ri_wr *)__skb_put(skb, sizeof(*wqe));
+	wqe = __skb_put(skb, sizeof(*wqe));
 	memset(wqe, 0, sizeof *wqe);
 	wqe->op_compl = cpu_to_be32(FW_WR_OP_V(FW_RI_INIT_WR));
 	wqe->flowid_len16 = cpu_to_be32(
@@ -1350,7 +1350,7 @@ static int rdma_fini(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 
 	set_wr_txq(skb, CPL_PRIORITY_DATA, ep->txq_idx);
 
-	wqe = (struct fw_ri_wr *)__skb_put(skb, sizeof(*wqe));
+	wqe = __skb_put(skb, sizeof(*wqe));
 	memset(wqe, 0, sizeof *wqe);
 	wqe->op_compl = cpu_to_be32(
 		FW_WR_OP_V(FW_RI_INIT_WR) |
@@ -1419,7 +1419,7 @@ static int rdma_init(struct c4iw_dev *rhp, struct c4iw_qp *qhp)
 	}
 	set_wr_txq(skb, CPL_PRIORITY_DATA, qhp->ep->txq_idx);
 
-	wqe = (struct fw_ri_wr *)__skb_put(skb, sizeof(*wqe));
+	wqe = __skb_put(skb, sizeof(*wqe));
 	memset(wqe, 0, sizeof *wqe);
 	wqe->op_compl = cpu_to_be32(
 		FW_WR_OP_V(FW_RI_INIT_WR) |