scst: Unbreak the build for kernel versions <= 6.3

The previous series of patches introduced the use of a const pointer to
scsi_host_template. However, scsi_host_alloc() uses a non-const pointer
prior to kernel version 6.4, causing the build to throw the following
error:

    passing argument 1 of ‘scsi_host_alloc’ discards ‘const’
    qualifier from pointer target type

Hence, cast away the constness to resolve the error.

scst_local/scst_local.c

@@ -1425,7 +1425,8 @@ static int scst_local_driver_probe(struct device *dev)
 
 	TRACE_DBG("sess %p", sess);
 
-	hpnt = scsi_host_alloc(&scst_lcl_ini_driver_template, sizeof(*sess));
+	hpnt = scsi_host_alloc((struct scsi_host_template *) &scst_lcl_ini_driver_template,
+				sizeof(*sess));
 	if (hpnt == NULL) {
 		PRINT_ERROR("%s", "scsi_register() failed");
 		ret = -ENODEV;