COMPMID-1141 Fix segfault in 'NEON/MeanStdDev/RunLarge@Shape=1245x652:Format=U8'

Change-Id: I345ddb7fdb8d37126dc465d821f8a1c62856ac6d
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/130865
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/tests/benchmark/fixtures/MeanStdDevFixture.h b/tests/benchmark/fixtures/MeanStdDevFixture.h
index 9fb6585..95ff17d 100644
--- a/tests/benchmark/fixtures/MeanStdDevFixture.h
+++ b/tests/benchmark/fixtures/MeanStdDevFixture.h
@@ -46,10 +46,6 @@
         // Create tensors
         src = create_tensor<TensorType>(shape, format);
 
-        // Create output variables
-        float mean    = 0.0f;
-        float std_dev = 0.0f;
-
         // Create and configure function
         mean_std_dev_func.configure(&src, &mean, &std_dev);
 
@@ -75,6 +71,8 @@
 private:
     TensorType src{};
     Function   mean_std_dev_func{};
+    float      mean{ 0.0f };
+    float      std_dev{ 0.0f };
 };
 } // namespace benchmark
 } // namespace test