audit: simplify audit_enabled check in audit_watch_log_rule_change()

Check the audit_enabled flag and bail immediately.  This does not change
the functionality, but brings the code format in line with similar
checks in audit_tree_log_remove_rule(), audit_mark_log_rule_change(),
and elsewhere in the audit code.

See: https://github.com/linux-audit/audit-kernel/issues/50

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

kernel/audit_watch.c

@@ -238,20 +238,21 @@ out:
 
 static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op)
 {
-	if (audit_enabled) {
-		struct audit_buffer *ab;
-		ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
-		if (unlikely(!ab))
-			return;
-		audit_log_format(ab, "auid=%u ses=%u op=%s",
-				 from_kuid(&init_user_ns, audit_get_loginuid(current)),
-				 audit_get_sessionid(current), op);
-		audit_log_format(ab, " path=");
-		audit_log_untrustedstring(ab, w->path);
-		audit_log_key(ab, r->filterkey);
-		audit_log_format(ab, " list=%d res=1", r->listnr);
-		audit_log_end(ab);
-	}
+	struct audit_buffer *ab;
+
+	if (!audit_enabled)
+		return;
+	ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
+	if (!ab)
+		return;
+	audit_log_format(ab, "auid=%u ses=%u op=%s",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current), op);
+	audit_log_format(ab, " path=");
+	audit_log_untrustedstring(ab, w->path);
+	audit_log_key(ab, r->filterkey);
+	audit_log_format(ab, " list=%d res=1", r->listnr);
+	audit_log_end(ab);
 }
 
 /* Update inode info in audit rules based on filesystem event. */