[NET]: Memory barrier cleanups

I believe all the below memory barriers only matter on SMP so
therefore the smp_* variant of the barrier should be used.

I'm wondering if the barrier in net/ipv4/inet_timewait_sock.c should be
dropped entirely.  schedule_work's implementation currently implies a
memory barrier and I think sane semantics of schedule_work() should imply
a memory barrier, as needed so the caller shouldn't have to worry.
It's not quite obvious why the barrier in net/packet/af_packet.c is
needed; maybe it should be implied through flush_dcache_page?

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 08e68b6..da73e8a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -660,7 +660,7 @@
 	sll->sll_ifindex = dev->ifindex;
 
 	h->tp_status = status;
-	mb();
+	smp_mb();
 
 	{
 		struct page *p_start, *p_end;