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/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 9a0bdf9..d0b5c7a 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1344,7 +1344,6 @@
  *	@field contains the field which relates to current LSM.
  *	@op contains the operator that will be used for matching.
  *	@rule points to the audit rule that will be checked against.
- *	@actx points to the audit context associated with the check.
  *	Return 1 if secid matches the rule, 0 if it does not, -ERRNO on failure.
  *
  * @audit_rule_free:
@@ -1764,8 +1763,7 @@
 	int (*audit_rule_init)(u32 field, u32 op, char *rulestr,
 				void **lsmrule);
 	int (*audit_rule_known)(struct audit_krule *krule);
-	int (*audit_rule_match)(u32 secid, u32 field, u32 op, void *lsmrule,
-				struct audit_context *actx);
+	int (*audit_rule_match)(u32 secid, u32 field, u32 op, void *lsmrule);
 	void (*audit_rule_free)(void *lsmrule);
 #endif /* CONFIG_AUDIT */