qa/tasks/vstart_runner: make remote.sh return str as default

To address the issue in https://github.com/ceph/teuthology/pull/1459.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
(cherry picked from commit 624944503e7c6aa246331f4d9f291cf714296380)

diff --git a/qa/tasks/vstart_runner.py b/qa/tasks/vstart_runner.py
index cf6aaa123d55485ed5faf5bfbeedb96525e8bf59..65b8070e9103a820a29bfee214967fa176939add 100644 (file)
--- a/qa/tasks/vstart_runner.py
+++ b/qa/tasks/vstart_runner.py
@@ -318,7 +318,7 @@ class LocalRemote(object):
             remote_date = remote.sh('date')
         """
         if 'stdout' not in kwargs:
-            kwargs['stdout'] = BytesIO()
+            kwargs['stdout'] = StringIO()
         if 'args' not in kwargs:
             kwargs['args'] = script
         proc = self.run(**kwargs)