TOMOYO: Do not call tomoyo_realpath_init unless registered.

tomoyo_realpath_init() is unconditionally called by security_initcall().
But nobody will use realpath related functions if TOMOYO is not registered.

So, let tomoyo_init() call tomoyo_realpath_init().

This patch saves 4KB of memory allocation if TOMOYO is not registered.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 5fd48d2..d47f16b 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -371,10 +371,8 @@
 
 /**
  * tomoyo_realpath_init - Initialize realpath related code.
- *
- * Returns 0.
  */
-static int __init tomoyo_realpath_init(void)
+void __init tomoyo_realpath_init(void)
 {
 	int i;
 
@@ -388,11 +386,8 @@
 	if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
 		panic("Can't register tomoyo_kernel_domain");
 	up_read(&tomoyo_domain_list_lock);
-	return 0;
 }
 
-security_initcall(tomoyo_realpath_init);
-
 /* Memory allocated for temporary purpose. */
 static atomic_t tomoyo_dynamic_memory_size;