client: make statestore and fstore consistent with server
There should not be mixed statestore as global variable and as local
function parameter. This commit fixes usage of sysrestore and statestore
as local variables only. In future we may need to change default
statestore and fstore depending on where the functions are called and
this change makes it easier and less error prone.
Reviewed-By: Stanislav Laznicka <firstname.lastname@example.org>