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/salsa20_generic.c b/crypto/salsa20_generic.c
index 9a4770c..3d0f9df 100644
--- a/crypto/salsa20_generic.c
+++ b/crypto/salsa20_generic.c
@@ -248,4 +248,4 @@
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm");
-MODULE_ALIAS("salsa20");
+MODULE_ALIAS_CRYPTO("salsa20");