qa/tasks/fwd_scrub: remove unnecessary traceback

Fixes: https://tracker.ceph.com/issues/65820
Signed-off-by: Neeraj Pratap Singh <[email protected]>

Author: neeraj pratap singh

qa/tasks/fwd_scrub.py

@@ -33,6 +33,8 @@ def __init__(self, fs, scrub_timeout=300, sleep_between_iterations=1):
     def _run(self):
         try:
             self.do_scrub()
+        except ThrasherGreenlet.Stopped:
+            pass
         except Exception as e:
             self.set_thrasher_exception(e)
             self.logger.exception("exception:")