gfs2: simplify gdlm_put_lock with out_free label

This patch introduces a new out_free label and consolidates the three
places function gdlm_put_lock freed the glock.  No change in
functionality.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>