crypto: blowfish - split generic and common c code

Patch splits up the blowfish crypto routine into a common part (key setup)
which will be used by blowfish crypto modules (x86_64 assembly and generic-c).

Also fixes errors/warnings reported by checkpatch.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>