pinctrl: cy8c95x0: Avoid returning positive values to user space

pinctrl: cy8c95x0: Avoid returning positive values to user space

When probe fails due to unclear interrupt status register, it returns
a positive number instead of the proper error code. Fix this accordingly.

Fixes: e6cbbe42944d ("pinctrl: Add Cypress cy8c95x0 support")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202602271847.vVWkqLBD-lkp@intel.com/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>