Core: Get rid of Host_GetInstance()

Source/Core/Core/BootManager.cpp

@@ -74,8 +74,6 @@ bool BootCore(const std::string& _rFilename)
 	StartUp.bRunCompareClient = false;
 	StartUp.bRunCompareServer = false;
 
-	StartUp.hInstance = Host_GetInstance();
-
 	// This is saved seperately from everything because it can be changed in SConfig::AutoSetup()
 	config_cache.bHLE_BS2 = StartUp.bHLE_BS2;