Wait until child process will be killed

It might take a wile to kill worker after receiving of sighup because
of worker can be busy at the time, so the check of the workers count
can be failed during some amount of time.
Add timeout for checking.

Change-Id: Ibdd29b07960b2f765b03ea9458b6e85cd6786fd0
Closes-bug: #1472531
2 files changed
tree: 559465052b25e4f9810ba3c11803f18f9ff42f8b
  1. common/
  2. functional/
  3. scenario/