netfilter: ebtables: avoid explicit XT_ALIGN() in match/targets

This will cause trouble once CONFIG_COMPAT support is added to ebtables.
xt_compat_*_offset() calculate the kernel/userland structure size delta
using:

XT_ALIGN(size) - COMPAT_XT_ALIGN(size)

If the match/target sizes are aligned at registration time,
delta is always zero.

Should have zero effect for existing systems: xtables uses
XT_ALIGN() whenever it deals with match/target sizes.

Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>