da9030_battery: Don't use 0 as NULL
da9030_battery: Don't use 0 as NULL

Noticed the new warning:

  CHECK   drivers/power/da9030_battery.c
drivers/power/da9030_battery.c:190:68: warning: Using plain integer as NULL pointer

This commit fixes the issue.

Signed-off-by: Anton Vorontsov <1aae5ab9541d66245293c8fc1b9880f5df073631@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs