xfs: remove xfs_dqrele_all_inodes

xfs_dqrele_all_inodes is unused now, remove it and all supporting code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>