sha1-mb-x86_64.pl: fix typo.

Reviewed-by: Emilia Kasper <emilia@openssl.org>
crypto/evp/e_aes_cbc_hmac_sha[1|256].c: fix compiler warnings.

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
PR2490: Remove unused local variable bn ecp_nist.c

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>