fix klocwork issues: Add return 0 for int main()

main in IpmbSensor.cpp was missed last time.
Add it now to resolve Klocwork issue.

Signed-off-by: Zhikui Ren <zhikui.ren@intel.com>
Change-Id: I89763b39204dc14bd904669e3abc239d55c9ea7a
diff --git a/src/IpmbSensor.cpp b/src/IpmbSensor.cpp
index 22e4862..f52f95e 100644
--- a/src/IpmbSensor.cpp
+++ b/src/IpmbSensor.cpp
@@ -646,4 +646,5 @@
 
     setupManufacturingModeMatch(*systemBus);
     io.run();
+    return 0;
 }