[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/appletalk/ddp.c b/net/appletalk/ddp.c
index 7c0b515..e0d37d6 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1044,7 +1044,7 @@
 	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 		goto out;
 	rc = -ENOMEM;
-	sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
+	sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
 	if (!sk)
 		goto out;
 	rc = 0;