Remove flags and tunalready arguments from ipsec4_process_packet()
and make its prototype similar to ipsec6_process_packet.
The flags argument isn't used here, tunalready is always zero.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275708 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f