ipv6: do compat setsockopt for MCAST_MSFILTER directly

similar to the ipv4 counterpart of that patch - the same
trick used to align the tail array properly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-03-30 16:40:04 -04:00
commit 168a2cca81