GCC diagnostics were added to ignore array boundaries, instead
of ignoring GCC warning current code will check for array boundaries
and perform and array update only for valid elements.

Resolves: `CID 246574` `CID 246710` `CID 246651`

Signed-off-by: Deepika Bhavnani <deepika.bhavnani@arm.com>
Change-Id: I7530ecf7a1707351c6ee87e90cc3d33574088f57