xfs: remove unused tr_swrite

tr_swrite is never used, remove it.

From a very quick look, I think the usage of it (and its ancestor
XFS_SWRITE_LOG_RES) went away in commit 13e6d5cd "xfs: merge fsync
and O_SYNC handling" back in 2009.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_trans_resv.c

@@ -784,7 +784,6 @@ xfs_trans_resv_calc(
 	/* The following transaction are logged in logical format */
 	resp->tr_ichange.tr_logres = xfs_calc_ichange_reservation(mp);
 	resp->tr_growdata.tr_logres = xfs_calc_growdata_reservation(mp);
-	resp->tr_swrite.tr_logres = xfs_calc_swrite_reservation(mp);
 	resp->tr_fsyncts.tr_logres = xfs_calc_swrite_reservation(mp);
 	resp->tr_writeid.tr_logres = xfs_calc_writeid_reservation(mp);
 	resp->tr_attrsetrt.tr_logres = xfs_calc_attrsetrt_reservation(mp);

fs/xfs/xfs_trans_resv.h

@@ -42,7 +42,6 @@ struct xfs_trans_resv {
 	struct xfs_trans_res	tr_ifree;	/* inode free trans */
 	struct xfs_trans_res	tr_ichange;	/* inode update trans */
 	struct xfs_trans_res	tr_growdata;	/* fs data section grow trans */
-	struct xfs_trans_res	tr_swrite;	/* sync write inode trans */
 	struct xfs_trans_res	tr_addafork;	/* add inode attr fork trans */
 	struct xfs_trans_res	tr_writeid;	/* write setuid/setgid file */
 	struct xfs_trans_res	tr_attrinval;	/* attr fork buffer