crc32-generic doesn't have a cra_alignmask set, which is desired as its
->update() works with any alignment.  However, it incorrectly assumes
4-byte alignment in ->setkey() and when outputting the final digest.

Fix this by using the unaligned access macros in those cases.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>