scsi: remove the use_clustering flag

The same effects can be achieved by setting the dma_boundary to
PAGE_SIZE - 1 and the max_segment_size to PAGE_SIZE, so shift those
settings into the drivers.  Note that in many cases the setting might
be bogus, but this keeps the status quo.

[mkp: fix myrs and myrb]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 23354f2..0175684 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -980,7 +980,7 @@ static struct scsi_host_template iscsi_sw_tcp_sht = {
 	.eh_abort_handler       = iscsi_eh_abort,
 	.eh_device_reset_handler= iscsi_eh_device_reset,
 	.eh_target_reset_handler = iscsi_eh_recover_target,
-	.use_clustering         = DISABLE_CLUSTERING,
+	.dma_boundary		= PAGE_SIZE - 1,
 	.slave_alloc            = iscsi_sw_tcp_slave_alloc,
 	.slave_configure        = iscsi_sw_tcp_slave_configure,
 	.target_alloc		= iscsi_target_alloc,