[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/x25/af_x25.c b/net/x25/af_x25.c
index fc416f9..92cfe8e 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -472,7 +472,7 @@
 static struct sock *x25_alloc_socket(struct net *net)
 {
 	struct x25_sock *x25;
-	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, 1);
+	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto);
 
 	if (!sk)
 		goto out;