Fix file name handling in bundle_adjust_tracks
Fix file name handling in bundle_adjust_tracks

Fix porting error from 22dcab9722c2 where getting the filename without
suffix was incorrectly changed to getting the directory name. This broke
association of input KRTD files to input frame images, and may have also
caused KRTD output to erroneously write only a single output file with
the wrong name.

linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk,linus-sherrill/maptk