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

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: 0f04a81784fe ("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@44f7ab9e8d59
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>