bitbake: knotty: Avoid looping with tracebacks

If there are events queued and there is an exception in the main loop
of the UI code, it will print tracebacks on the console indefinitely.
Avoid that by improving the loop exit conditions.

(Bitbake rev: 2d0940b920a22b244f3ba6849c7cd019578386b4)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/knotty.py

@@ -630,15 +630,13 @@ def main(server, eventHandler, params, tf = TerminalFilter):
     termfilter = tf(main, helper, console_handlers, params.options.quiet)
     atexit.register(termfilter.finish)
 
-    while True:
+    while main.shutdown < 2:
         try:
             if (lastprint + printinterval) <= time.time():
                 termfilter.keepAlive(printinterval)
                 printinterval += printintervaldelta
             event = eventHandler.waitEvent(0)
             if event is None:
-                if main.shutdown > 1:
-                    break
                 if not parseprogress:
                     termfilter.updateFooter()
                 event = eventHandler.waitEvent(0.25)