Fix QA mixup of node/instance tests

There are two node tests that are run from RunCommonInstanceTests, which is the
bad place—it causes these node tests to be run three times instead of once.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

qa/ganeti-qa.py

@@ -213,15 +213,20 @@ def RunCommonInstanceTests(instance):
   if qa_config.TestEnabled('tags'):
     RunTest(qa_tags.TestInstanceTags, instance)
 
+  if qa_rapi.Enabled():
+    RunTest(qa_rapi.TestInstance, instance)
+
+
+def RunCommonNodeTests():
+  """Run a few common node tests.
+
+  """
   if qa_config.TestEnabled('node-volumes'):
     RunTest(qa_node.TestNodeVolumes)
 
   if qa_config.TestEnabled("node-storage"):
     RunTest(qa_node.TestNodeStorage)
 
-  if qa_rapi.Enabled():
-    RunTest(qa_rapi.TestInstance, instance)
-
 
 def RunExportImportTests(instance, pnode, snode):
   """Tries to export and import the instance.
@@ -363,6 +368,8 @@ def main():
   if qa_config.TestEnabled('tags'):
     RunTest(qa_tags.TestClusterTags)
 
+  RunCommonNodeTests()
+
   pnode = qa_config.AcquireNode(exclude=qa_config.GetMasterNode())
   try:
     if qa_config.TestEnabled('node-readd'):