Fix build warnings for CentOS 6.0

sources/centos60/dns_resolve.c

@@ -224,7 +224,7 @@ failed_put_cred:
 	return ret;
 }
 
-void __exit cifs_exit_dns_resolver(void)
+void cifs_exit_dns_resolver(void)
 {
 	key_revoke(dns_resolver_cache->thread_keyring);
 	unregister_key_type(&key_type_dns_resolver);

sources/centos60/dns_resolve.h

@@ -27,7 +27,7 @@
 #include <linux/module.h>
 
 extern int __init cifs_init_dns_resolver(void);
-extern void __exit cifs_exit_dns_resolver(void);
+extern void cifs_exit_dns_resolver(void);
 extern int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr);
 #endif /* KERNEL */