[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/unix/af_unix.c b/net/unix/af_unix.c
index 9163ec5..515e7a6 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -602,7 +602,7 @@
 	if (atomic_read(&unix_nr_socks) >= 2*get_max_files())
 		goto out;
 
-	sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto, 1);
+	sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
 	if (!sk)
 		goto out;