pass stop_on_error to _has_error_in_logs

we missed to pass over the stop_on_error boolean to the function

Change-Id: I7dfc413ff37f9315d74bcade1c022f157ec8c4c0
diff --git a/tempest/stress/driver.py b/tempest/stress/driver.py
index 55404ce..b5cab68 100644
--- a/tempest/stress/driver.py
+++ b/tempest/stress/driver.py
@@ -196,7 +196,7 @@
 
         if not logfiles:
             continue
-        if _has_error_in_logs(logfiles, computes):
+        if _has_error_in_logs(logfiles, computes, stop_on_error):
             had_errors = True
             break