crypto: prefix module autoloading with "crypto-"

This prefixes all crypto module loading with "crypto-" so we never run
the risk of exposing module auto-loading to userspace via a crypto API,
as demonstrated by Mathias Krause:

https://lkml.org/lkml/2013/3/4/70

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
index 1dc54bb..a203191 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -145,9 +145,9 @@
 	.coa_decompress		=	null_compress } }
 } };
 
-MODULE_ALIAS("compress_null");
-MODULE_ALIAS("digest_null");
-MODULE_ALIAS("cipher_null");
+MODULE_ALIAS_CRYPTO("compress_null");
+MODULE_ALIAS_CRYPTO("digest_null");
+MODULE_ALIAS_CRYPTO("cipher_null");
 
 static int __init crypto_null_mod_init(void)
 {