pinctrl: mcp23s08: Split to three parts: fix ptr_ret.cocci warnings

drivers/pinctrl/pinctrl-mcp23s08_spi.c:129:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

Fixes: 0f04a817 ("pinctrl: mcp23s08: Split to three parts: core, I²C, SPI")
Signed-off-by: kernel test robot <lkp@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200608010253.GA79576@44f7ab9e8d59Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-mcp23s08_spi.c

@@ -126,10 +126,7 @@ static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev,
 	copy->name = name;
 
 	mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
-	if (IS_ERR(mcp->regmap))
-		return PTR_ERR(mcp->regmap);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(mcp->regmap);
 }
 
 static int mcp23s08_probe(struct spi_device *spi)