slapos_cloud: Make Pylint Happy

master/bt5/slapos_cloud/SkinTemplateItem/portal_skins/slapos_cloud/SoftwareRelease_getUsableComputerWithoutSInstanceList.py

-list = []
-for si in context.portal_catalog(url_string=context.getUrlString(), portal_type='Software Installation', validation_state='validated'):
+computer_list = []
+for si in context.portal_catalog(url_string=context.getUrlString(),
+                                 portal_type='Software Installation',
+                                 validation_state='validated'):
   computer = si.getAggregateValue()
   if si.getSlapState() == 'start_requested' and \
       not computer.Computer_getSoftwareReleaseUsage(context.getUrlString()) \
       and computer.getValidationState() == 'validated':
-    list.append(computer)
+    computer_list.append(computer)
 
-return list
+return computer_list