don't shutdown logging, just flush the fd

vm/kojikamid

@@ -655,12 +655,13 @@ def incremental_upload(server, handler):
 
 def flunk(server, logfile):
     """do the right thing when a build fails"""
+    global logfd
     logging.getLogger('koji.vm').error('error running build', exc_info=True)
     exc_info = sys.exc_info()
     tb = ''.join(traceback.format_exception(*exc_info))
     if server is not None:
         try:
-            logging.shutdown()
+            logfd.flush()
             upload_file(server, os.path.dirname(logfile),
                         os.path.basename(logfile))
         except: