Merge branch 'tl/pack-bitmap-absolute-paths'

The pack-bitmap machinery is taught to log the paths of redundant
bitmap(s) to trace2 instead of stderr.

* tl/pack-bitmap-absolute-paths:
  pack-bitmap.c: trace bitmap ignore logs when midx-bitmap is found
  pack-bitmap.c: break out of the bitmap loop early if not tracing
  pack-bitmap.c: avoid exposing absolute paths
  pack-bitmap.c: remove unnecessary "open_pack_index()" calls