crypto: msm: check potential integer overflow

According to the specification of AEAD, AEAD request crypt length is
not a fixed maximum and associated length is also same. This could
lead to potential integer overflow, thus allocating less memory. So
we need to check potential integer overflow on AEAD request length.

Signed-off-by: William Clark <wclark@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>