force abspath for path options

Deeper in the code, a chdir occurs- it shouldn't, but rather than
try to keep people behaving, just convert any given path to absolute.

BUG=None
TEST=ctest --target_image my-image.bin

Change-Id: I53e0ee89d1d65c85168176d21b112521b9c165b6
Reviewed-on: https://gerrit.chromium.org/gerrit/13563
Tested-by: Brian Harring <ferringb@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Ready: Brian Harring <ferringb@chromium.org>
1 file changed