Some tests need to run single tests for every available machine of the
current QEMU binary. To avoid code duplication, let's extract this
code that deals with 'query-machines' into a separate function.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1490860207-8302-3-git-send-email-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>