Today, md5sum fails with error -ENOKEY because a setkey
function is set for non hmac hashing algs, see strace output below:

mmap(NULL, 378880, PROT_READ, MAP_SHARED, 6, 0) = 0x77f50000
accept(3, 0, NULL)                      = 7
vmsplice(5, [{"bin/\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 378880}], 1, SPLICE_F_MORE|SPLICE_F_GIFT) = 262144
splice(4, NULL, 7, NULL, 262144, SPLICE_F_MORE) = -1 ENOKEY (Required key not available)
write(2, "Generation of hash for file kcap"..., 50) = 50
munmap(0x77f50000, 378880)              = 0

This patch ensures that setkey() function is set only
for hmac hashing.

Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>