security/integrity: make ima/ima_mok.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

ima/Kconfig:config IMA_MOK_KEYRING
ima/Kconfig: bool "Create IMA machine owner keys (MOK) and blacklist keyrings"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple of traces of modularity so that when reading the
driver there is no doubt it really is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Mimi Zohar <[email protected]>
Cc: Dmitry Kasatkin <[email protected]>
Cc: James Morris <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Paul Gortmaker <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

security/integrity/ima/ima_mok.c

@@ -16,7 +16,7 @@
 #include <linux/sched.h>
 #include <linux/cred.h>
 #include <linux/err.h>
-#include <linux/module.h>
+#include <linux/init.h>
 #include <keys/asymmetric-type.h>
 
 
@@ -52,5 +52,4 @@ __init int ima_mok_init(void)
 	set_bit(KEY_FLAG_KEEP, &ima_blacklist_keyring->flags);
 	return 0;
 }
-
-module_init(ima_mok_init);
+device_initcall(ima_mok_init);