Make sure the cached OpenCL profile file actually matches the devices present

Re-evaluate scores if the profile file did not match.

It used to work so that if the OpenCL devices available had changed (if just
the OpenCL driver version had changed), we did not re-evaluate scores but
instead selected the dummy software device. Which hardly was as intended.

Change-Id: Ifd79c0226504323f275d2e1d02876a0fecc449e0