unaligned access in sk_run_filter()

This patch fixes unaligned access warnings noticed on IA64
in sk_run_filter(). 'ptr' can be unaligned.

Signed-off-By: Dmitry Mishin <dim@openvz.org>
Signed-off-By: Kirill Korotaev <dev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>