Btrfs-progs: delete bogus dir indexes

Btrfs-progs: delete bogus dir indexes

We may run across dir indexes that are corrupt in such a way that it makes them
useless, such as having a bad location key or a bad name.  In this case we can
just delete dir indexes that don't show up properly and then re-create what we
need.  When we delete dir indexes however we need to restart scanning the fs
tree as we could have greated bogus inode recs if the location key was bad, so
set it up so that if we had to delete an dir index we go ahead and free up our
inode recs and return -EAGAIN to check_fs_roots so it knows to restart the loop.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.cz>