apparmor: Fix kernel-doc warnings in apparmor/match.c

Fix kernel-doc warnings:

security/apparmor/match.c:148: warning: Function parameter or member
'tables' not described in 'verify_table_headers'
security/apparmor/match.c:289: warning: Excess function parameter
'kr' description in 'aa_dfa_free_kref'
security/apparmor/match.c:289: warning: Function parameter or member
'kref' not described in 'aa_dfa_free_kref'

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>