Small wording changes and fix checks.

Reviewed-by: iustinp

qa/qa-sample.yaml

@@ -38,8 +38,10 @@ tests:
   node-info: True
   node-volumes: True
 
-  # These tests need at least three nodes
+  # This test needs at least three nodes
   node-evacuate: False
+
+  # This test needs at least two nodes
   node-failover: False
 
   instance-add-plain-disk: True

qa/qa_node.py

@@ -88,7 +88,7 @@ def TestNodeFailover(node, node2):
   """gnt-node failover"""
   master = qa_config.GetMasterNode()
 
-  if qa_utils.GetNodeInstances(node2):
+  if qa_utils.GetNodeInstances(node2, secondaries=False):
     raise qa_errors.UnusableNodeError("Secondary node has at least one "
                                       "primary instance. This test requires "
                                       "it to have no primary instances.")
@@ -110,7 +110,7 @@ def TestNodeEvacuate(node, node2):
 
   node3 = qa_config.AcquireNode(exclude=[node, node2])
   try:
-    if qa_utils.GetNodeInstances(node3):
+    if qa_utils.GetNodeInstances(node3, secondaries=True):
       raise qa_errors.UnusableNodeError("Evacuation node has at least one "
                                         "secondary instance. This test requires "
                                         "it to have no secondary instances.")