Remove unnecessary log message

This commit removes a useless log message from call_until_true. The
debug log there provides no useful debug information, just printing
that the sleep loop iterated doesn't enable any extra debugging. In
the worst case it ends up polluting the logs with the same message
while the loop times out. So let's just remove it.

Closes-Bug: #1336591
Change-Id: Ia0cec5c699470554a25c077082878772158f4c5a
Merge "Remove unnecessary log message"