crypto: include crypto- module prefix in template

This adds the module loading prefix "crypto-" to the template lookup
as well.

For example, attempting to load 'vfat(blowfish)' via AF_ALG now correctly
includes the "crypto-" prefix at every level, correctly rejecting "vfat":

	net-pf-38
	algif-hash
	crypto-vfat(blowfish)
	crypto-vfat(blowfish)-all
	crypto-vfat

Reported-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>