Do not use skip_checks in TestServerAdvancedOps
Do not use skip_checks in TestServerAdvancedOps

if CONF.compute.flavor_ref_alt == CONF.compute.flavor_ref,
test_server_sequence_suspend_resume will be skipped unexpectedly,
so the skip judgement shouldn't be put in skip_checks.

Besides, if flavor_ref_alt is not set, the resize testcase should
also be skipped.

Change-Id: I6bc3680ffa8c440590e234ce17bb57f06b361d02

vedujoshi/tempest,masayukig/tempest,openstack/tempest,cisco-openstack/tempest,masayukig/tempest,Juniper/tempest,vedujoshi/tempest,cisco-openstack/tempest,openstack/tempest,Juniper/tempest