IVGCVSW-4246 Clean build of profiling with -Wextra Pt2

Change-Id: Iae306546e7c009105712f177943ed76451bbe8e7
Signed-off-by: Derek Lamberti <derek.lamberti@arm.com>
diff --git a/src/profiling/CounterDirectory.cpp b/src/profiling/CounterDirectory.cpp
index 5a69e1c..6b2a945 100644
--- a/src/profiling/CounterDirectory.cpp
+++ b/src/profiling/CounterDirectory.cpp
@@ -9,6 +9,7 @@
 #include <armnn/Exceptions.hpp>
 #include <armnn/Conversion.hpp>
 
+#include <boost/core/ignore_unused.hpp>
 #include <boost/format.hpp>
 
 namespace armnn
@@ -285,6 +286,8 @@
                                                  const Optional<uint16_t>& deviceUid,
                                                  const Optional<uint16_t>& counterSetUid)
 {
+    boost::ignore_unused(backendId);
+
     // Check that the given parent category name is valid
     if (parentCategoryName.empty() ||
             !IsValidSwTraceString<SwTraceNameCharPolicy>(parentCategoryName))