can: at91_can: Use of_match_ptr()

of_match_ptr() eliminates having an #ifdef returning NULL for the case
when OF is disabled.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index ce8421a..dbbe97a 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -1264,8 +1264,6 @@
 	}
 };
 MODULE_DEVICE_TABLE(of, at91_can_dt_ids);
-#else
-#define at91_can_dt_ids NULL
 #endif
 
 static const struct at91_devtype_data *at91_can_get_driver_data(struct platform_device *pdev)
@@ -1424,7 +1422,7 @@
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.owner = THIS_MODULE,
-		.of_match_table = at91_can_dt_ids,
+		.of_match_table = of_match_ptr(at91_can_dt_ids),
 	},
 	.id_table = at91_can_id_table,
 };