【fix sonar】SysUserDepartServiceImpl文件

jero-boot/jero-boot-module-system/src/main/java/com/jero/modules/system/service/impl/SysUserDepartServiceImpl.java

@@ -16,10 +16,7 @@ import com.jero.modules.system.service.ISysUserService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.stream.Collectors;
 
 /**
@@ -66,7 +63,7 @@ public class SysUserDepartServiceImpl extends ServiceImpl<SysUserDepartMapper, S
 		}catch(Exception e) {
 			e.fillInStackTrace();
 		}
-		return null;
+		return Collections.emptyList();
 
 
 	}