[CIPSO]: Fix several unaligned kernel accesses in the CIPSO engine.

IPv4 options are not very well aligned within the packet and the
format of a CIPSO option is even worse.  The result is that the CIPSO
engine in the kernel does a few unaligned accesses when parsing and
validating incoming packets with CIPSO options attached which generate
error messages on certain alignment sensitive platforms.  This patch
fixes this by marking these unaligned accesses with the
get_unaliagned() macro.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>