Fix Coverity #343008, Side affect in assertion

This patch simply splits off the increment of next_xlat into a separate
statement to ensure consistent behaviour if the assert was to ever be
removed.

Change-Id: I827f601ccea55f4da9442048419c9b8cc0c5d22e
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>
1 file changed