Fix 拼写错误

mooctest-site-server/src/main/java/cn/iselab/mooctest/site/web/ctrl/ExamController.java

@@ -420,9 +420,9 @@ public class ExamController extends BaseSearchController {
     public ExamVO deleteExamById(@PathVariable("examId") Long examId){
         Long userId = (Long) SecurityUtils.getSubject().getSession().getAttribute("userId");
         String permissionStr = userId + ":task:delete:" + examId;
-        boolean havaPermissionToDelete = SecurityUtils.getSubject().isPermitted(new ExamPermission(permissionStr));
+        boolean havePermissionToDelete = SecurityUtils.getSubject().isPermitted(new ExamPermission(permissionStr));
         boolean isAdmin = SecurityUtils.getSubject().hasRole("admin");
-        if (havaPermissionToDelete || isAdmin) {
+        if (havePermissionToDelete || isAdmin) {
             return examLogic.deleteExamById(examId);
         }else {
             throw new UnauthenticatedException("Operation forbidden!");