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/api.c b/crypto/api.c
index a2b39c5..2a81e98 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -216,11 +216,11 @@
 
 	alg = crypto_alg_lookup(name, type, mask);
 	if (!alg) {
-		request_module("%s", name);
+		request_module("crypto-%s", name);
 
 		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
 		      CRYPTO_ALG_NEED_FALLBACK))
-			request_module("%s-all", name);
+			request_module("crypto-%s-all", name);
 
 		alg = crypto_alg_lookup(name, type, mask);
 	}