can: flexcan: disable runtime PM if register flexcandev failed

Disable runtime PM if register flexcandev failed, and balance reference
of usage_count.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20200929211557.14153-4-qiangqing.zhang@nxp.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/flexcan.c

@@ -2057,6 +2057,8 @@ static int flexcan_probe(struct platform_device *pdev)
 	return 0;
 
  failed_register:
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 	free_candev(dev);
 	return err;
 }