ksmbd: Use AES-CMAC library for SMB3 signature calculation

ksmbd: Use AES-CMAC library for SMB3 signature calculation

Now that AES-CMAC has a library API, convert ksmbd_sign_smb3_pdu() to
use it instead of a "cmac(aes)" crypto_shash.

The result is simpler and faster code.  With the library there's no need
to dynamically allocate memory, no need to handle errors, and the
AES-CMAC code is accessed directly without inefficient indirect calls
and other unnecessary API overhead.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>