Fix logging in Health HAL 2.0

Bug: 149577800
Test: Ensure logging works as expected
Change-Id: I79b78593ee6bdbda59e49a27e70076184a30668d
diff --git a/health/2.0/default/Health.cpp b/health/2.0/default/Health.cpp
index 4225fd8..65eada8 100644
--- a/health/2.0/default/Health.cpp
+++ b/health/2.0/default/Health.cpp
@@ -156,7 +156,7 @@
     const HealthInfo_1_0& health_info = battery_monitor_->getHealthInfo_1_0();
     struct BatteryProperties props;
     convertFromHealthInfo(health_info, &props);
-    bool log = healthd_board_battery_update(&props);
+    bool log = (healthd_board_battery_update(&props) == 0);
     if (log) {
         battery_monitor_->logValues();
     }