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

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

Fix kernel-doc warnings:

security/apparmor/file.c:177: warning: Excess function parameter
'dfa' description in 'aa_lookup_fperms'
security/apparmor/file.c:177: warning: Function parameter or member
'file_rules' not described in 'aa_lookup_fperms'
security/apparmor/file.c:202: warning: Excess function parameter
'dfa' description in 'aa_str_perms'
security/apparmor/file.c:202: warning: Excess function parameter
'state' description in 'aa_str_perms'
security/apparmor/file.c:202: warning: Function parameter or member
'file_rules' not described in 'aa_str_perms'
security/apparmor/file.c:202: warning: Function parameter or member
'start' not described in 'aa_str_perms'

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