tests/qtest/cdrom-test: Improve the machine detection in the cdrom test

When configuring QEMU with the --without-default-devices switch, these
tests are currently failing since they assume that the "pc" and "q35"
machines are always available. Add some proper checks to make the test
work without these machines, too.

Message-ID: <20240905191434.694440-3-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
1 file changed