LU-4102 utils: add dry-run to ll_recover_lost_found_objs

LU-4102 utils: add dry-run to ll_recover_lost_found_objs

Add the dry-run (-n) option to ll_recover_lost_found_objs.  This
allows scanning an OST filesystem without modifying it.

It is now possible to test both the "lost+found/" directory, as well
as the "O/" directory to verify the LMA and FID xattrs on existing
objects that are in the normal filesystem hierarchy.

Fix verbose (-v) option to print all of the inodes being checked.
This option previously did nothing.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I8e2b427046c6acf5cf7429f41ccd57496c500c1e
Reviewed-on: http://review.whamcloud.com/8061
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>