Pretty print fiemap flags in filerec-test.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Rename filerec-test target to show-shared-extents.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
The extent search status bar never showed 100% completion - we needed to
send one last update from find_all_dups.

The bar updates are choppy. This is probably because we update on each
bucket, and the hash buckets can be various sizes. Update instead on the
total number of blocks hashed. This doesn't fix the choppiness completely,
but does smooth it out a bit more.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>