COMPMID-2177 Fix clang warnings

Change-Id: I78039db8c58d7b14a042c41e54c25fb9cb509bf7
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1092
Reviewed-by: VidhyaSudhan Loganathan <vidhyasudhan.loganathan@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validate_examples/graph_depthwiseconvolution.cpp b/tests/validate_examples/graph_depthwiseconvolution.cpp
index cdad404..1f5627a 100644
--- a/tests/validate_examples/graph_depthwiseconvolution.cpp
+++ b/tests/validate_examples/graph_depthwiseconvolution.cpp
@@ -224,6 +224,7 @@
     /** Default destructor */
     ~DepthConvolutionOptions() override = default;
 
+private:
     SimpleOption<int>                                          *width;              /**< Input width */
     SimpleOption<int>                                          *height;             /**< Input height */
     SimpleOption<int>                                          *channels;           /**< Input channels */