Btrfs: release both paths before logging dir/changed extents

The ceph guys tripped over this bug where we were still holding onto the
original path that we used to copy the inode with when logging.  This is based
on Chris's fix which was reported to fix the problem.  We need to drop the paths
in two cases anyway so just move the drop up so that we don't have duplicate
code.  Thanks,

Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>