message: Add an assertion for Async request status
diff: @@ -209,8 +209,10 @@ class dnn_test(NewOpenCVTests):
  outs.insert(0, netAsync.forwardAsync())
  for i in reversed(range(numInputs)):
  - if outs[i].wait_for(timeout) == 1:
  + ret = outs[i].wait_for(timeout)
  + if ret == 1:
  self.fail("Timeout")
  + self.assertEqual(ret, 0) # is ready
  normAssert(self, refs[i], outs[i].get(), 'Index: %d' % i, 1e-10)
  