power: supply: rt5033_battery: Fix error code in rt5033_battery_probe()

In the function rt5033_battery_probe(), it should return -ENOMEM
instead of -EINVAL when call function devm_kzalloc() failed.

Signed-off-by: Peng Fan <fanpeng@loongson.cn>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>