s3c_adc_battery: Fix annotation for s3c_adc_battery_probe()

A probe() function is used at device init time rather than system init
time.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>