audit: convert audit_ever_enabled to a boolean

We were treating it as a boolean, let's make it a boolean to help
avoid future mistakes.

Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/kernel/audit.c b/kernel/audit.c
index e75918f..f0cf9bf 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -86,7 +86,7 @@ static int	audit_initialized;
 #define AUDIT_ON	1
 #define AUDIT_LOCKED	2
 u32		audit_enabled = AUDIT_OFF;
-u32		audit_ever_enabled = !!AUDIT_OFF;
+bool		audit_ever_enabled = !!AUDIT_OFF;
 
 EXPORT_SYMBOL_GPL(audit_enabled);