bitbake: cooker: Ensure parser is cleaned up

During cooker shutdown, its possible the parser isn't cleaned up. Fix
this (which may partially explain why threads were left hanging around
at exit).

(Bitbake rev: fe1b57f4d39c287526353387e164c863eb9df421)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cooker.py

@@ -1636,6 +1636,7 @@ class BBCooker:
         return
 
     def post_serve(self):
+        self.shutdown(force=True)
         prserv.serv.auto_shutdown()
         if self.hashserv:
             self.hashserv.process.terminate()