shared: Update types and style
shared: Update types and style

Change response type to match what deserialization expects, this is
fine as we always expect 8 bit bytes and 8 bit chars.

Also annotate an unused variable and fix style to checking a
function's return value after assigning it to a local variable.

Signed-off-by: William Douglas <07dd1d6cf12120bb0585d2eb50da402be35d56e5@intel.com>

sofar/buxton,sofar/buxton