modify if-statement to satisfy pmd check

src/main/java/com/alibaba/excel/write/property/ExcelWriteHeadProperty.java

@@ -158,9 +158,8 @@ public class ExcelWriteHeadProperty extends ExcelHeadProperty {
                 int lastCol = i;
                 int lastRow = j;
                 for (int k = i + 1; k < headList.size(); k++) {
-                    if (headList.get(k).getHeadNameList().get(j).equals(headName)
-                        && (j - 1 >= 0)
-                        && !headList.get(k).getHeadNameList().get(j-1).equals(headName)) {
+                    boolean flag = (j - 1 >= 0) && !headList.get(k).getHeadNameList().get(j - 1).equals(headName);
+                    if (headList.get(k).getHeadNameList().get(j).equals(headName) && flag) {
                         alreadyRangeSet.add(k + "-" + j);
                         lastCol = k;
                     } else {