We can delete the redundant type conversion if
we set the the AES_KEY parameter with 'const' in
qcrypto_cipher_aes_ecb_(en|de)crypt() function.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>