change $trenType to $trendMethod in case TREND_BEST_FIT

Author: quonly

src/PhpSpreadsheet/Shared/Trend/Trend.php

@@ -94,7 +94,7 @@ public static function calculate(string $trendType = self::TREND_BEST_FIT, array
                 $bestFit = [];
                 $bestFitValue = [];
                 foreach (self::$trendTypes as $trendMethod) {
-                    $className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendType . 'BestFit';
+                    $className = '\PhpOffice\PhpSpreadsheet\Shared\Trend\\' . $trendMethod . 'BestFit';
                     //* @phpstan-ignore-next-line
                     $bestFit[$trendMethod] = new $className($yValues, $xValues, $const);
                     $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();