COMPMID-418 Add check and fix comments after preprocessor conditions

Change-Id: I1353fd652ee180e3931e58b4ce13d651a48c7e2c
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/79567
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Moritz Pflanzer <moritz.pflanzer@arm.com>
diff --git a/arm_compute/core/CL/CLHelpers.h b/arm_compute/core/CL/CLHelpers.h
index 7b3af33..5234ae1 100644
--- a/arm_compute/core/CL/CLHelpers.h
+++ b/arm_compute/core/CL/CLHelpers.h
@@ -103,4 +103,4 @@
  */
 GPUTarget get_arch_from_target(GPUTarget target);
 }
-#endif
+#endif /* __ARM_COMPUTE_CLHELPERS_H__ */