xfs: put the open zone later xfs_open_zone_put

xfs: put the open zone later xfs_open_zone_put

The open zone is what holds the rtg reference for us.  This doesn't
matter until we support shrinking, and even then is rather theoretical
because we can't shrink away a just filled zone in a tiny race window,
but let's play safe here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>