Correct few pipeline_barrier tests

Correct few pipeline_barrier tests

In pipeline barrier tests there is findMaxBufferSize util function.
It consists of two parts. First part checks if we can create buffer
that requires as much space as we want to test, and second, used when
first part fails, searches for maximal buffer that we can create
within that limit. Since test values are multiply of 1024 the second
part of this function was never hit by most of implementations.
It was hit by implementation that overalocates buffers and this
revealed that classes operating on ubo and ssbo were not handling
buffer sizes that are not multiple of 16 in case of ssbo and multiple
of 1024 in case of ubo (rest of RenderPassCommands are handling that
case). Note that this can be tested by just commenting first part of
findMaxBufferSize function.
This change make sure that ubo and ssbo tests work on smaller buffers
but with limitation that last modulo 16 values from those buffers are
not used in tests.

Components: Vulkan

VK-GL-CTS public issue: 206

Affects:
dEQP-VK.memory.pipeline_barrier.*uniform_buffer.*
dEQP-VK.memory.pipeline_barrier.*storage_buffer.*

Change-Id: Ia7d09500116783ac9ea047d18690efa329d625e7