scsi: rename SCSI_MAX_{SG, SG_CHAIN}_SEGMENTS

Rename SCSI_MAX_SG_SEGMENTS to SG_CHUNK_SIZE, which means the amount
we fit into a single scatterlist chunk.

Rename SCSI_MAX_SG_CHAIN_SEGMENTS to SG_MAX_SEGMENTS.

Will move these 2 generic definitions to scatterlist.h later.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bart Van Assche <bart.vanassche@sandisk.com> (for ib_srp changes)
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index f3d69a98..06b1517 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5305,7 +5305,7 @@
 	.eh_host_reset_handler = scsi_debug_host_reset,
 	.can_queue =		SCSI_DEBUG_CANQUEUE,
 	.this_id =		7,
-	.sg_tablesize =		SCSI_MAX_SG_CHAIN_SEGMENTS,
+	.sg_tablesize =		SG_MAX_SEGMENTS,
 	.cmd_per_lun =		DEF_CMD_PER_LUN,
 	.max_sectors =		-1U,
 	.use_clustering = 	DISABLE_CLUSTERING,