Avoid bashizm in AbsolutePath() function

&> is another bashizm. Avoid that since configure is run using POSIX
shell. Some POSIX compatible shells like mksh do not understand bash
syntax.

"cd - &> /dev/null" was causing "cd -" command to go into background
which means we never changed back to original directory thus fooling
configure script later:

config.status: error: cannot find input file: `config_host.mk.in'

"&>" was also redirecting stderr which we don't want to do anymore since
it hides real and interesting errors.

Change-Id: I286a32e6a200afca883b159d9196f606e0fe7063
Reviewed-on: https://gerrit.libreoffice.org/11896
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>