Revert "Temporary fix to script hang"

This reverts commit bc8b34c4e550c3e56d8d7e43aacf903daa1cac51.
We have been unable to reproduce the problem that this change works around.
So we are going to revert the code and keep a close eye on regress test
jobs to make sure the shell is not hanging.

Change-Id: Iad59786d3f713a8ac5723da6fd040bd9eddcd703