fish: Pass cfgs to blameq

This open-coding of three separate things, with blameq having magic
knowledge of which one is which, is completely wrong.  blameq should
take a list.  The various Xdb Xdbk should in the cfgs too.

A step towards this is for blameq to get the cfgs.

No functional change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>