COMPMID-837: Fixed remap tests failures in Valgrind.

Some minor improvements in the test fixture, for example making sure
the values in the mapx and mapy tensors are in the range of [-5, in_width+5]
and [-5,in_height].

Tolerance was changed to 0, no mismatches expected.

Change-Id: I2fad06defb293bf9fdd1988799b19547c102dee5
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/118044
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/tests/validation/NEON/Remap.cpp b/tests/validation/NEON/Remap.cpp
index 6e58000..2e54b11 100644
--- a/tests/validation/NEON/Remap.cpp
+++ b/tests/validation/NEON/Remap.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -43,8 +43,8 @@
 {
 namespace
 {
-constexpr AbsoluteTolerance<uint8_t> tolerance_value(1);
-constexpr float                      tolerance_number = 0.2f;
+constexpr AbsoluteTolerance<uint8_t> tolerance_value(0);
+constexpr float                      tolerance_number = 0.f;
 } // namespace
 
 TEST_SUITE(NEON)