[NET]: Forget the zero_it argument of sk_alloc()

Finally, the zero_it argument can be completely removed from
the callers and from the function prototype.

Besides, fix the checkpatch.pl warnings about using the
assignments inside if-s.

This patch is rather big, and it is a part of the previous one.
I splitted it wishing to make the patches more readable. Hope 
this particular split helped.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 6fbbae7..477e052 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -607,7 +607,7 @@
 {
 	struct sock *sk;
 
-	sk = sk_alloc(net, PF_BLUETOOTH, prio, &l2cap_proto, 1);
+	sk = sk_alloc(net, PF_BLUETOOTH, prio, &l2cap_proto);
 	if (!sk)
 		return NULL;