IVGCVSW-4482 Remove boost::ignore_unused

* replaced boost::ignore_unused with armnn::IgnoreUnused

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: I4443a3620ed7d51b151af67c070d4225e410b5fa
diff --git a/test/Lstm.hpp b/test/Lstm.hpp
index d3e03d7..3ac095d 100644
--- a/test/Lstm.hpp
+++ b/test/Lstm.hpp
@@ -7,6 +7,8 @@
 
 #include "DriverTestHelpers.hpp"
 
+#include <armnn/utility/IgnoreUnused.hpp>
+
 #include <boost/array.hpp>
 #include <boost/math/special_functions/relative_difference.hpp>
 
@@ -2371,7 +2373,7 @@
 template <typename HalPolicy>
 void QuantizedLstm(armnn::Compute compute)
 {
-    boost::ignore_unused(compute);
+    armnn::IgnoreUnused(compute);
     // This replicates android/frameworks/ml/nn/runtime/test/generated/vts_models/quantized_lstm.model.cpp
     // with values from android/frameworks/ml/nn/runtime/test/generated/examples/quantized_lstm.example.cpp
     // and weights, biases and scalars passed as CONSTANT_COPY tensors (instead of MODEL_INPUT tensors).