qa/tasks/vstart_runner.py: use StringIO for capturing text

to be consistent with 8bfe977854686149c74de3ebaed7b571d43404dd

Fixes: https://tracker.ceph.com/issues/45246
Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/qa/tasks/vstart_runner.py b/qa/tasks/vstart_runner.py
index d6a69066255e6e3b0654591e66316ec0c46aae0d..88ebd0f088ba769ddcb61693aa7c457e17662103 100644 (file)
--- a/qa/tasks/vstart_runner.py
+++ b/qa/tasks/vstart_runner.py
@@ -940,7 +940,7 @@ class LocalCephManager(CephManager):
         if watch_channel is not None:
             args.append("--watch-channel")
             args.append(watch_channel)
-        proc = self.controller.run(args=args, wait=False, stdout=BytesIO())
+        proc = self.controller.run(args=args, wait=False, stdout=StringIO())
         return proc
 
     def raw_cluster_cmd(self, *args, **kwargs):