netfilter: x_tables: xt_compat_match_from_user doesn't need a retval

[ Upstream commit 0188346f21e6546498c2a0f84888797ad4063fc5 ]

Always returned 0.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>