power: supply: cpcap-battery: Simplify short term power average calculation

static int cpcap_battery_cc_get_avg_current(struct cpcap_battery_ddata *ddata)

{

	int value, acc, error;

	s32 sample = 1;

	s32 sample;

	s16 offset;

	if (ddata->vendor == CPCAP_VENDOR_ST)

		sample = 4;

	/* Coulomb counter integrator */

	error = regmap_read(ddata->reg, CPCAP_REG_CCI, &value);

	if (error)

		return error;

	if ((ddata->vendor == CPCAP_VENDOR_TI) && (value > 0x2000))

		value = value | 0xc000;

	if (ddata->vendor == CPCAP_VENDOR_TI) {

		acc = sign_extend32(value, 13);

		sample = 1;

	} else {

		acc = (s16)value;

		sample = 4;

	}

	/* Coulomb counter sample time */

	/* Coulomb counter calibration offset  */

	error = regmap_read(ddata->reg, CPCAP_REG_CCM, &value);

	if (error)

		return error;

	if (value < 0x200)

		offset = value;

	else

		offset = value | 0xfc00;

	offset = sign_extend32(value, 9);

	return cpcap_battery_cc_to_ua(ddata, sample, acc, offset);

}