Setting up the arguments may consume some of the arguments, e.g. if we
provide a config file or extra modules, then the test harness is
expected to be responsible for freeing those arguments.

Checking the requirements and bailing first means that we never do that,
and thus skipped tests result in leaks. Flip the order so we set up the
args first and skip last, so we can consistently take ownership of all
the provided setup parameters.

Signed-off-by: Daniel Stone <daniels@collabora.com>