估计容量小于0后，校准容量到最小容量

Signed-off-by: huhui <huhui@sharkgulf.com>

Application/app/sox/soc.c

@@ -410,7 +410,7 @@ static void soc_update_by_current_and_time(float current_now, float delta_time,
 	double est_coulomb = _soc.coulomb_now + delta_q;//计算当前容量，充电加, 放电减
 
 	if (est_coulomb < 0){
-		est_coulomb = 0;
+		est_coulomb = _soc.coulomb_min;
 	}else if (est_coulomb > _soc.coulomb_max) {
 		est_coulomb = _soc.coulomb_max;
 	}