IVGCVSW-4482 Remove boost::ignore_unused

!referencetests:229377

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: Ia9b360b4a057fe7bbce5b268092627c09a0dba82
diff --git a/src/armnn/optimizations/ConvertConstants.hpp b/src/armnn/optimizations/ConvertConstants.hpp
index b3842e3..5e19c7b 100644
--- a/src/armnn/optimizations/ConvertConstants.hpp
+++ b/src/armnn/optimizations/ConvertConstants.hpp
@@ -11,7 +11,7 @@
 
 #include <backendsCommon/CpuTensorHandle.hpp>
 
-#include <boost/core/ignore_unused.hpp>
+#include <armnn/utility/IgnoreUnused.hpp>
 
 #include <Half.hpp>
 
@@ -72,7 +72,7 @@
 
     void Run(Graph& graph, Layer& layer) const override
     {
-        boost::ignore_unused(graph);
+        IgnoreUnused(graph);
         if (Predicate::Test(layer))
         {
             layer.OperateOnConstantTensors(Converter::Func);