(svn r12197) -Fix [FS#1788](r12134): show correct last year profit when the train had negative income

-Codechange: use GetDisplayProfitThisYear() to convert vehicle profit to readable form

src/economy.cpp

@@ -163,14 +163,16 @@ int UpdateCompanyRatingAndValue(Player *p, bool update)
 				num++;
 				if (v->age > 730) {
 					/* Find the vehicle with the lowest amount of profit */
-					if (min_profit_first || min_profit > v->profit_last_year >> 8) {
-						min_profit = v->profit_last_year >> 8;
+					if (min_profit_first || min_profit > v->profit_last_year) {
+						min_profit = v->profit_last_year;
 						min_profit_first = false;
 					}
 				}
 			}
 		}
 
+		min_profit >>= 8; // remove the fract part
+
 		_score_part[owner][SCORE_VEHICLES] = num;
 		/* Don't allow negative min_profit to show */
 		if (min_profit > 0)