qa/tasks: make sh() in vstart_runner.py identical with teuthology.orc…

…hestra.remote.sh

Fixes: https://tracker.ceph.com/issues/46069
Signed-off-by: Jos Collin <jcollin@redhat.com>

qa/tasks/vstart_runner.py

@@ -422,7 +422,7 @@ def _do_run(self, args, check_status=True, wait=True, stdout=None,
 
         return proc
 
-    # XXX: for compatibility keep this method same teuthology.orchestra.remote.sh
+    # XXX: for compatibility keep this method same as teuthology.orchestra.remote.sh
     def sh(self, script, **kwargs):
         """
         Shortcut for run method.
@@ -432,12 +432,15 @@ def sh(self, script, **kwargs):
             remote_date = remote.sh('date')
         """
         if 'stdout' not in kwargs:
-            kwargs['stdout'] = StringIO()
+            kwargs['stdout'] = BytesIO()
         if 'args' not in kwargs:
             kwargs['args'] = script
         proc = self.run(**kwargs)
-        return proc.stdout.getvalue()
-
+        out = proc.stdout.getvalue()
+        if isinstance(out, bytes):
+            return out.decode()
+        else:
+            return out
 
 class LocalDaemon(object):
     def __init__(self, daemon_type, daemon_id):