Remove usage of valid window region CL - NHWC

Resolves: COMPMID-4153

Change-Id: Ib0d60c9acaac8aaf3946c62fc2d740b5ec6cee5c
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5301
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/CL/kernels/CLReductionOperationKernel.cpp b/src/core/CL/kernels/CLReductionOperationKernel.cpp
index 2697a0d..a5734d4 100644
--- a/src/core/CL/kernels/CLReductionOperationKernel.cpp
+++ b/src/core/CL/kernels/CLReductionOperationKernel.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2020 Arm Limited.
+ * Copyright (c) 2017-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -94,7 +94,6 @@
                 AccessWindowStatic     input_access(input, 0, 0, input->dimension(0) + border_width, 1);
                 AccessWindowHorizontal output_access(output, 0, 1);
                 window_changed = update_window_and_padding(win, input_access, output_access);
-                output_access.set_valid_region(win, ValidRegion(Coordinates(), output->tensor_shape()));
             }
         }
         break;
@@ -105,7 +104,6 @@
             AccessWindowHorizontal input_access(input, 0, num_elems_processed_per_iteration);
             AccessWindowHorizontal output_access(output, 0, num_elems_processed_per_iteration);
             window_changed = update_window_and_padding(win, input_access, output_access);
-            output_access.set_valid_region(win, ValidRegion(Coordinates(), output->tensor_shape()));
         }
         break;
         default: