update 学生乐保增加，删除和修改

mec-web/src/main/java/com/ym/mec/web/controller/StudentInstrumentController.java

@@ -137,7 +137,7 @@ public class StudentInstrumentController extends BaseController {
     @ApiOperation(value = "删除学生乐器信息")
     @PostMapping("/del")
     @PreAuthorize("@pcs.hasPermissions('studentInstrument/del')")
-    public HttpResponseResult<StudentInstrument> update(Long id, Integer studentId) {
+    public HttpResponseResult<StudentInstrument> del(Long id, Integer studentId) {
         SysUser sysUser = sysUserFeignService.queryUserInfo();
         if (sysUser == null) {
             return failed("用户信息获取失败");