Move variable function in lsm_audit.h into SMACK private space

Moved variable function in include/linux/lsm_audit.h into the
smack_audit_data struct since it is never used outside of it.

Also removed setting of function in the COMMON_AUDIT_DATA_INIT
macro because that variable is now private to SMACK.

Signed-off-by: Thomas Liu <tliu@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
I-dont-see-any-problems-with-it: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 513dc1a..dd84877 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -241,7 +241,8 @@
 {
 	struct common_audit_data *ad = a;
 	struct smack_audit_data *sad = &ad->lsm_priv.smack_audit_data;
-	audit_log_format(ab, "lsm=SMACK fn=%s action=%s", ad->function,
+	audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
+			 ad->lsm_priv.smack_audit_data.function,
 			 sad->result ? "denied" : "granted");
 	audit_log_format(ab, " subject=");
 	audit_log_untrustedstring(ab, sad->subject);
@@ -274,8 +275,8 @@
 	if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
 		return;
 
-	if (a->function == NULL)
-		a->function = "unknown";
+	if (a->lsm_priv.smack_audit_data.function == NULL)
+		a->lsm_priv.smack_audit_data.function = "unknown";
 
 	/* end preparing the audit data */
 	sad = &a->lsm_priv.smack_audit_data;