can: tcan4x5x: tcan4x5x_can_probe(): add missing error checking for devm_regmap_init()

This patch adds the missing error checking when initializing the regmap
interface fails.

Fixes: 5443c226 ("can: tcan4x5x: Add tcan4x5x driver to the kernel")
Cc: Dan Murphy <dmurphy@ti.com>
Link: http://lore.kernel.org/r/20201019154233.1262589-7-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/m_can/tcan4x5x.c

@@ -487,6 +487,10 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 
 	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
 					&spi->dev, &tcan4x5x_regmap);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		goto out_clk;
+	}
 
 	ret = tcan4x5x_power_enable(priv->power, 1);
 	if (ret)