As a general rule, we prefer avoiding implicit global state
because it makes code harder to safely copy and paste without
thinking about the global state.  Adjust the helper code to
use explicit state instead, and update all callers.

bios-tables-test no longer depends on global_qtest, now that it
passes explicit state through the testsuite data; an assert
proves this fact (although we will get rid of it later, once
global_qtest is gone).
Signed-off-by: NEric Blake <eblake@redhat.com>
Acked-by: NIgor Mammedov <imammedo@redhat.com>
Tested-by: NIgor Mammedov <imammedo@redhat.com>
[thuth: adapted patch to current master branch]
Signed-off-by: NThomas Huth <thuth@redhat.com>