The script needs two files to open:

  $(builddir)/test_file_access.txt, and
  $(srcdir)/file_access_whitelist.txt.

However, the script is opening the files from the $CWD which
won't work for a VPATH build. Make the script accept paths to the
files through @ARGV and tune the Makefile.am to pass them.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>