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/sensors/host.cpp b/sensors/host.cpp
index 9cc1eee..b0e08b1 100644
--- a/sensors/host.cpp
+++ b/sensors/host.cpp
@@ -91,7 +91,7 @@
     return r;
 }
 
-void HostSensor::write(double value)
+void HostSensor::write([[maybe_unused]] double value)
 {
     throw std::runtime_error("Not Implemented.");
 }