fix compile warning when meson build

- Fix compile warning:
  [-Werror=unused-variable], [-Werror=sign-compare] and
  deprecated INSTANTIATE_TEST_CASE_P

Signed-off-by: Harvey.Wu <Harvey.Wu@quantatw.com>
Change-Id: If8713f0b938cd5306bbe19a9078731db0c3667dc
diff --git a/test/pid_zone_unittest.cpp b/test/pid_zone_unittest.cpp
index 172c818..275dfe6 100644
--- a/test/pid_zone_unittest.cpp
+++ b/test/pid_zone_unittest.cpp
@@ -558,11 +558,12 @@
     EXPECT_CALL(sdbus_mock_mode,
                 sd_bus_emit_properties_changed_strv(
                     IsNull(), StrEq(objPath), StrEq(modeInterface), NotNull()))
-        .WillOnce(Invoke([&](sd_bus* bus, const char* path,
-                             const char* interface, const char** names) {
-            EXPECT_STREQ("Manual", names[0]);
-            return 0;
-        }));
+        .WillOnce(Invoke(
+            [&]([[maybe_unused]] sd_bus* bus, [[maybe_unused]] const char* path,
+                [[maybe_unused]] const char* interface, const char** names) {
+                EXPECT_STREQ("Manual", names[0]);
+                return 0;
+            }));
 
     // Method under test will set the manual mode to true and broadcast this
     // change on dbus.