Fix incorrect memory handling in ported functions

Details of the functions:
- ClSoftmax
- CpuSoftmax
- CpuPool2d

Change-Id: Icd2c14d5df010c3b2301e2693ce6f414d7c61916
Resolves: COMPMID-4404
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5797
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/runtime/cpu/operators/CpuPool2d.h b/src/runtime/cpu/operators/CpuPool2d.h
index ae3d115..68416b5 100644
--- a/src/runtime/cpu/operators/CpuPool2d.h
+++ b/src/runtime/cpu/operators/CpuPool2d.h
@@ -80,7 +80,7 @@
 
     bool                             _is_global_pooling_layer;
     DataLayout                       _data_layout;
-    experimental::MemoryRequirements _mem_req;
+    experimental::MemoryRequirements _aux_mem{};
 };
 } // namespace cpu
 } // namespace arm_compute