fscrypt: remove loadable module related code

Since commit 643fa961 ("fscrypt: remove filesystem specific build
config option"), fs/crypto/ can no longer be built as a loadable module.
Thus it no longer needs a module_exit function, nor a MODULE_LICENSE.
So remove them, and change module_init to late_initcall.
Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

fs/crypto/crypto.c

@@ -510,22 +510,4 @@ static int __init fscrypt_init(void)
 fail:
 	return -ENOMEM;
 }
-module_init(fscrypt_init)
-
-/**
- * fscrypt_exit() - Shutdown the fs encryption system
- */
-static void __exit fscrypt_exit(void)
-{
-	fscrypt_destroy();
-
-	if (fscrypt_read_workqueue)
-		destroy_workqueue(fscrypt_read_workqueue);
-	kmem_cache_destroy(fscrypt_ctx_cachep);
-	kmem_cache_destroy(fscrypt_info_cachep);
-
-	fscrypt_essiv_cleanup();
-}
-module_exit(fscrypt_exit);
-
-MODULE_LICENSE("GPL");
+late_initcall(fscrypt_init)

fs/crypto/fscrypt_private.h

@@ -166,6 +166,4 @@ struct fscrypt_mode {
 	bool needs_essiv;
 };
 
-extern void __exit fscrypt_essiv_cleanup(void);
-
 #endif /* _FSCRYPT_PRIVATE_H */

fs/crypto/keyinfo.c

@@ -437,11 +437,6 @@ static int init_essiv_generator(struct fscrypt_info *ci, const u8 *raw_key,
 	return err;
 }
 
-void __exit fscrypt_essiv_cleanup(void)
-{
-	crypto_free_shash(essiv_hash_tfm);
-}
-
 /*
  * Given the encryption mode and key (normally the derived key, but for
  * FS_POLICY_FLAG_DIRECT_KEY mode it's the master key), set up the inode's