fix getLimitedScaleX

Author: ggggxiaolong

MPChartLib/src/main/java/com/github/mikephil/charting/listener/BarLineChartTouchListener.java

@@ -443,6 +443,7 @@ private void performZoom(MotionEvent event) {
      */
     private float getLimitedScaleX(float scaleX, MPPointF t) {
         ViewPortHandler h = mChart.getViewPortHandler();
+		tempMatrix.set(mSavedMatrix);
         tempMatrix.postScale(scaleX, 1f, t.x, t.y);
 
         mSavedMatrix.getValues(matrixBuffer);