When iterating over the used LRs, be careful not to try to access
an unused LR, or even an unimplemented one if you're unlucky...
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>