audit: remove unused actx param from audit_rule_match

The audit_rule_match() struct audit_context *actx parameter is not used
by any in-tree consumers (selinux, apparmour, integrity, smack).

The audit context is an internal audit structure that should only be
accessed by audit accessor functions.

It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic
Audit LSM hooks") but appears to have never been used.

Remove it.

Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/107

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the referenced commit title]
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 430d4f3..403513d 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4393,13 +4393,11 @@
  * @field: audit rule flags given from user-space
  * @op: required testing operator
  * @vrule: smack internal rule presentation
- * @actx: audit context associated with the check
  *
  * The core Audit hook. It's used to take the decision of
  * whether to audit or not to audit a given object.
  */
-static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
-				  struct audit_context *actx)
+static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
 {
 	struct smack_known *skp;
 	char *rule = vrule;