Fix member name in PadDescriptor

* Renamed m_padValue to m_PadValue to bring it in line with
  our naming conventions

Signed-off-by: Aron Virginas-Tar <Aron.Virginas-Tar@arm.com>
Change-Id: I071aa42c9be495462c64697e5a923a5ec55de146
diff --git a/src/backends/reference/workloads/RefPadWorkload.cpp b/src/backends/reference/workloads/RefPadWorkload.cpp
index 8cb9d88..e9724c4 100644
--- a/src/backends/reference/workloads/RefPadWorkload.cpp
+++ b/src/backends/reference/workloads/RefPadWorkload.cpp
@@ -30,7 +30,7 @@
     const T* inputData = GetInputTensorData<T>(0, m_Data);
     T* outputData = GetOutputTensorData<T>(0, m_Data);
 
-    Pad(inputInfo, outputInfo, m_Data.m_Parameters.m_PadList, inputData, outputData, m_Data.m_Parameters.m_padValue);
+    Pad(inputInfo, outputInfo, m_Data.m_Parameters.m_PadList, inputData, outputData, m_Data.m_Parameters.m_PadValue);
 }
 
 template class RefPadWorkload<DataType::Float32>;