Do not remove unavailable machines, this fixes:

  VirtioMaxSegSettingsCheck.test_machine_types: ERROR: list.remove(x): x not in list (0.12 s)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
TODO check how to use attribute (Wainer)
---
 tests/acceptance/virtio_check_params.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tests/acceptance/virtio_check_params.py b/tests/acceptance/virtio_check_params.py
index 5458573138..4a417b8ef5 100755
--- a/tests/acceptance/virtio_check_params.py
+++ b/tests/acceptance/virtio_check_params.py
@@ -109,14 +109,15 @@ class VirtioMaxSegSettingsCheck(Test):
         return False
 
     def test_machine_types(self):
-        # collect all machine types except 'none', 'isapc', 'microvm'
+        EXCLUDED_MACHINES = ['none', 'isapc', 'microvm']
+        # collect all machine types except the ones in EXCLUDED_MACHINES
         with QEMUMachine(self.qemu_bin) as vm:
             vm.launch()
             machines = [m['name'] for m in vm.command('query-machines')]
             vm.shutdown()
-        machines.remove('none')
-        machines.remove('isapc')
-        machines.remove('microvm')
+        for m in EXCLUDED_MACHINES:
+            if m in machines:
+                machines.remove(m)
 
         for dev_type in DEV_TYPES:
             # create the list of machine types and their parameters.
-- 
2.21.1