Btrfs: make sure to remove the orphan item from the in-memory list

This fixes a problem where if truncate fails the inode will still be on the in
memory orphan list.  This is will make us complain when the inode gets destroyed
because it's still on the orphan list.  So if we fail just remove us from the in
memory list and carry on.

Signed-off-by: Josef Bacik <josef@redhat.com>