Crypto/chcr: fix for ccm(aes) failed test

The ccm(aes) test fails when req->assoclen > ~240bytes.

The problem is the value assigned to auth_offset is wrong.
As auth_offset is unsigned char, it can take max value as 255.
So fix it by making it unsigned int.

Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Devulapally Shiva Krishna <shiva@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>