qtmod_test: fixed crash on Windows when qt.install.dir does not exist
qtmod_test: fixed crash on Windows when qt.install.dir does not exist

Fix for difference in abs_path behavior on Unix vs Windows.

Change-Id: I757e1c9f041dce2309e385a21034fdd2f6e3b29b
Reviewed-by: Sergio Ahumada <27ca633ce817d1c3858ceeac3c99febb78411853@nokia.com>
Reviewed-by: Toby Tomkins <23ead35e36f9890dd80f47acf9947179b1bd7fe7@nokia.com>

tsarajar/qtqa,tsarajar/qtqa,tsarajar/qtqa,tsarajar/qtqa