If CONFIG_GPIO_SYSFS=n, compilation fails with
drivers/built-in.o: In function `gpio_export_with_name':
include/asm-generic/gpio.h:128: undefined reference to `__gpiod_export'
This is because the stub in that case has the wrong name,
_gpiod_export() - note the missing underscore (_) at the
start.
Fix the stub, and add the correct prototype for the real
implementation.
Signed-off-by: André Draszik <git@andred.net>
