This commit replaces the 1 sec timeout by an infinite wait.
To properly handle application closing, a pipe is created and the
poll also waits for POLLIN event on it.
This allows to abort the infinite wait of poll by simply writing
a dummy byte to the pipe.

Change-Id: Ib340891f244a1b7bfb43b7c6ad866adfe260ec95
Reviewed-on: https://gerrit.libreoffice.org/4778Reviewed-by: Petr Mladek <pmladek@suse.cz>
Tested-by: Petr Mladek <pmladek@suse.cz>