xfs: delete duplicated tp->t_dqinfo null check and allocation

The function xfs_trans_mod_dquot_byino() wraps around
xfs_trans_mod_dquot() to account for quotas, and also there is the
function call chain xfs_trans_reserve_quota_bydquots -> xfs_trans_dqresv
-> xfs_trans_mod_dquot, both of them do the duplicated null check and
allocation. Thus we can delete the duplicated operation from them.

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_trans_dquot.c

@@ -143,9 +143,6 @@ xfs_trans_mod_dquot_byino(
 	    xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
 		return;
 
-	if (tp->t_dqinfo == NULL)
-		xfs_trans_alloc_dqinfo(tp);
-
 	if (XFS_IS_UQUOTA_ON(mp) && ip->i_udquot)
 		(void) xfs_trans_mod_dquot(tp, ip->i_udquot, field, delta);
 	if (XFS_IS_GQUOTA_ON(mp) && ip->i_gdquot)
@@ -698,7 +695,6 @@ xfs_trans_dqresv(
 	 * because we don't have the luxury of a transaction envelope then.
 	 */
 	if (tp) {
-		ASSERT(tp->t_dqinfo);
 		ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
 		if (nblks != 0)
 			xfs_trans_mod_dquot(tp, dqp,
@@ -752,9 +748,6 @@ xfs_trans_reserve_quota_bydquots(
 	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
 		return 0;
 
-	if (tp && tp->t_dqinfo == NULL)
-		xfs_trans_alloc_dqinfo(tp);
-
 	ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
 
 	if (udqp) {