scsi: Remove unused member cmd_pool for structure scsi_host_template

After commit e9c787e6 ("scsi: allocate scsi_cmnd structures as part of
struct request"), the member cmd_pool in structure scsi_host_template is
not used, so remove it.

Link: https://lore.kernel.org/r/1644561778-183074-5-git-send-email-chenxiang66@hisilicon.comReviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/scsi/scsi_host.h

@@ -16,7 +16,6 @@ struct completion;
 struct module;
 struct scsi_cmnd;
 struct scsi_device;
-struct scsi_host_cmd_pool;
 struct scsi_target;
 struct Scsi_Host;
 struct scsi_transport_template;
@@ -493,8 +492,6 @@ struct scsi_host_template {
 	 */
 	u64 vendor_id;
 
-	struct scsi_host_cmd_pool *cmd_pool;
-
 	/* Delay for runtime autosuspend */
 	int rpm_autosuspend_delay;
 };