fix klockwork issues

Add return 0 for int main()

Signed-off-by: Zhikui Ren <zhikui.ren@intel.com>
Change-Id: I4ff6ef571827b17b89ed653c420e7f9964ab42f5
diff --git a/src/ExitAirTempSensor.cpp b/src/ExitAirTempSensor.cpp
index 1cd55b8..c0aae42 100644
--- a/src/ExitAirTempSensor.cpp
+++ b/src/ExitAirTempSensor.cpp
@@ -1002,4 +1002,5 @@
     }
 
     io.run();
+    return 0;
 }