Remove unnecessary friend function

IOptimizedNetwork declares a friend function (CreatePreCompiledWorkloadTest)
that is not necessary as that function does not use any of the non-public
members of the class. I suspect this is leftover after a refactor,
as the function in question uses GetGraphForTesting() to access the
internals instead.

This friend declaration was causing me a compilation error as the namespace
of the declared friend function did not match the namespace of the definition.
Removing it solves the compilation error and tidies up the code.

Change-Id: I4aa893cb5108cd3b72ca355f725fe7a0cd053a7e
Signed-off-by: Rob Hughes <robert.hughes@arm.com>
diff --git a/include/armnn/INetwork.hpp b/include/armnn/INetwork.hpp
index 98c9f3f..d1d4744 100644
--- a/include/armnn/INetwork.hpp
+++ b/include/armnn/INetwork.hpp
@@ -720,12 +720,6 @@
                                          const OptimizerOptions& options,
                                          Optional<std::vector<std::string>&> messages);
 
-    template <typename PreCompiledWorkload, armnn::DataType dataType>
-    friend std::pair<armnn::IOptimizedNetworkPtr, std::unique_ptr<PreCompiledWorkload>> CreatePreCompiledWorkloadTest(
-        armnn::IWorkloadFactory& factory,
-        armnn::Graph& graph,
-        bool biasEnabled);
-
     IOptimizedNetwork(std::unique_ptr<Graph> graph, const ModelOptions& modelOptions);
 
     std::unique_ptr<OptimizedNetworkImpl> pOptimizedNetworkImpl;