COMPMID-959: Assembly kernel marks weights as unused when pretranspose

Change-Id: I15943c4c97457f4cc9bff3bb1cce8ad9a8d9ed38
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/130474
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/arm_compute/runtime/NEON/AssemblyHelper.h b/arm_compute/runtime/NEON/AssemblyHelper.h
index ee09ef5..39c20fa 100644
--- a/arm_compute/runtime/NEON/AssemblyHelper.h
+++ b/arm_compute/runtime/NEON/AssemblyHelper.h
@@ -100,6 +100,7 @@
         {
             ARM_COMPUTE_ERROR_ON(_pretranspose == nullptr || _pretranspose->buffer() == nullptr);
             _gemm_kernel_asm->pretranspose_B_array(reinterpret_cast<void *>(_pretranspose->buffer()), in1_ptr, ldb, multi_stride_b);
+            _b->mark_as_unused();
         }
 
         NEScheduler::get().schedule(_optimised_kernel.get(), Window::DimX);