entity-manager:Removed unused variable

The powerWasOn variable wasn't used, and its initializer isPowerOn()
requires a sdbusplus::match object which would require extra work to
create for testcases that may not even need to do power matches.

Tested:
No change in normal operation.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I6037e5919384228470cd550fc8d8b08979b4f414
diff --git a/include/EntityManager.hpp b/include/EntityManager.hpp
index 748c49b..3df208e 100644
--- a/include/EntityManager.hpp
+++ b/include/EntityManager.hpp
@@ -56,7 +56,6 @@
     sdbusplus::asio::object_server& objServer;
     std::function<void()> _callback;
     bool _passed = false;
-    bool powerWasOn = isPowerOn();
     DBusProbeObjectT dbusProbeObjects;
     std::vector<std::string> passedProbes;
 };