power: supply: rk817: Fix unsigned comparison with less than zero

The tmp is defined as u32 type, which results in invalid processing of
tmp<0 in function rk817_read_or_set_full_charge_on_boot(). Therefore,
drop the comparison.

drivers/power/supply/rk817_charger.c:828 rk817_read_or_set_full_charge_on_boot() warn: unsigned 'tmp' is never less than zero.
drivers/power/supply/rk817_charger.c:788 rk817_read_or_set_full_charge_on_boot() warn: unsigned 'tmp' is never less than zero.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3444
Reported-by: Abaci Robot <[e-mail]>
Signed-off-by: Jiapeng Chong <[e-mail]>
Tested-by: Chris Morgan <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/rk817_charger.c

···
 		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
 				 bulk_reg, 4);
 		tmp = get_unaligned_be32(bulk_reg);
-		if (tmp < 0)
-			tmp = 0;
 		boot_charge_mah = ADC_TO_CHARGE_UAH(tmp,
 						    charger->res_div) / 1000;
 		/*
···
 	regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
 			 bulk_reg, 4);
 	tmp = get_unaligned_be32(bulk_reg);
-	if (tmp < 0)
-		tmp = 0;
 	boot_charge_mah = ADC_TO_CHARGE_UAH(tmp, charger->res_div) / 1000;
 	regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_OCV_VOL_H,
 			 bulk_reg, 2);