COMPMID-786: Remove all the fill() calls in benchmarks

Filling buffers with random data takes a significant amount of time and in most cases doesn't affect the performance
We will therefore only keep fill() in the functions for which it matters

Change-Id: Ica34fe09941f27d6f0417f33176847febf722bc3
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/115892
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
diff --git a/tests/benchmark/fixtures/LeNet5Fixture.h b/tests/benchmark/fixtures/LeNet5Fixture.h
index 191daa2..5108042 100644
--- a/tests/benchmark/fixtures/LeNet5Fixture.h
+++ b/tests/benchmark/fixtures/LeNet5Fixture.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -49,7 +49,6 @@
         network.init(batches);
         network.build();
         network.allocate();
-        network.fill_random();
     }
 
     void run()