qcacmn: Fix for direct dma + ftm mode

This change fixes the null pointer dereference issues
observed when running spectral scan using direct dma
framework with ftm mode.

CRs-Fixed: 2214269
Change-Id: I06514b38b519da7eb972ff713feab97e7d5a9c29

target_if/direct_buf_rx/src/target_if_direct_buf_rx_main.c

@@ -694,6 +694,12 @@ QDF_STATUS target_if_direct_buf_rx_module_register(
 	}
 	direct_buf_rx_info("Dbr pdev obj %pK", dbr_pdev_obj);
 
+	if (!dbr_pdev_obj->dbr_mod_param &&
+	    (mod_id >= dbr_pdev_obj->num_modules)) {
+		direct_buf_rx_err("Module %d not supported in target", mod_id);
+		return QDF_STATUS_E_FAILURE;
+	}
+
 	dbr_pdev_obj->dbr_mod_param[mod_id].dbr_rsp_handler =
 			dbr_rsp_handler;