scsi: scsi_debug: Drop scsi_debug_bus_reset() NULL pointer checks

The checks for SCSI cmnd, SCSI device, and SCSI host are unnecessary, so
drop them. Likewise, drop the NULL check for sdbg_host.

The only caller is scsi_try_bus_reset() -> eh_bus_reset_handler(), and
there those pointers cannot be NULL.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-7-john.g.garry@oracle.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -5412,34 +5412,24 @@ static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)
 
 static int scsi_debug_bus_reset(struct scsi_cmnd *SCpnt)
 {
-	struct sdebug_host_info *sdbg_host;
+	struct scsi_device *sdp = SCpnt->device;
+	struct sdebug_host_info *sdbg_host = shost_to_sdebug_host(sdp->host);
 	struct sdebug_dev_info *devip;
-	struct scsi_device *sdp;
-	struct Scsi_Host *hp;
 	int k = 0;
 
 	++num_bus_resets;
-	if (!(SCpnt && SCpnt->device))
-		goto lie;
-	sdp = SCpnt->device;
+
 	if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
 		sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
-	hp = sdp->host;
-	if (hp) {
-		sdbg_host = shost_to_sdebug_host(hp);
-		if (sdbg_host) {
-			list_for_each_entry(devip,
-					    &sdbg_host->dev_info_list,
-					    dev_list) {
+
+	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
 		set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
 		++k;
 	}
-		}
-	}
+
 	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)
 		sdev_printk(KERN_INFO, sdp,
 			    "%s: %d device(s) found in host\n", __func__, k);
-lie:
 	return SUCCESS;
 }