Remove unused check

Remove unused check

This check is useless here. Remove it.

Also a year later there was a specification issue #1222 "Should
requiresDedicatedAllocation imply requiresDedicatedAllocation?"

That clarified this question and specification now contains
following paragraph totally invalidating this check:

When the implementation sets requiresDedicatedAllocation to VK_TRUE,
it must also set prefersDedicatedAllocation to VK_TRUE.

Update tests:
 * dEQP-VK.memory.requirements.dedicated_allocation.buffer.*
 * dEQP-VK.memory.requirements.dedicated_allocation.image.*

Components: Vulkan

VK-GL-CTS issue: 391

VK-GL-CTS public issue: 267

Change-Id: I557d3c0fac752ec2f42db7e6dcd78787a0c69a26