audit: eliminate audit_enabled magic number comparison

Remove comparison of audit_enabled to magic numbers outside of audit.

Related: https://github.com/linux-audit/audit-kernel/issues/86

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 69c7847..9334fbe 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -117,6 +117,9 @@
 
 extern void audit_log_session_info(struct audit_buffer *ab);
 
+#define AUDIT_OFF	0
+#define AUDIT_ON	1
+#define AUDIT_LOCKED	2
 #ifdef CONFIG_AUDIT
 /* These are defined in audit.c */
 				/* Public API */
@@ -202,7 +205,7 @@
 static inline void audit_log_task_info(struct audit_buffer *ab,
 				       struct task_struct *tsk)
 { }
-#define audit_enabled 0
+#define audit_enabled AUDIT_OFF
 #endif /* CONFIG_AUDIT */
 
 #ifdef CONFIG_AUDIT_COMPAT_GENERIC