ima: remove unused cleanup functions

IMA cannot be used as module and does not need __exit functions.
Removed them.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

security/integrity/ima/ima_init.c

@@ -90,8 +90,3 @@ int __init ima_init(void)
 
 	return ima_fs_init();
 }
-
-void __exit ima_cleanup(void)
-{
-	ima_fs_cleanup();
-}