xfs: refactor XFS_QMOPT_DQNEXT out of existence

There's only one caller of DQNEXT and its semantics can be moved into a
separate function, so create the function and get rid of the flag.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_dquot.h b/fs/xfs/xfs_dquot.h
index 2f536f3..303e71d 100644
--- a/fs/xfs/xfs_dquot.h
+++ b/fs/xfs/xfs_dquot.h
@@ -171,6 +171,8 @@ extern void		xfs_qm_adjust_dqlimits(struct xfs_mount *,
 					       struct xfs_dquot *);
 extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
 					xfs_dqid_t, uint, uint, xfs_dquot_t **);
+extern int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
+					uint type, struct xfs_dquot **dqpp);
 extern void		xfs_qm_dqput(xfs_dquot_t *);
 
 extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);