Do not use image index and semaphore when vkAcquireNextImageKHR fails

Do not use image index and semaphore when vkAcquireNextImageKHR fails

This change follows d9763f6a0, where vkAcquireNextImageKHR was allowed
to fail with VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXT error.
However, the (not) acquired image index and semaphore was still used,
causing fauilure when validating the index.

This change skips using the image index and semaphore, when image was
not acquired.

Moreover, failure to acquire the image is logged as quality warning.

VK-GL-CTS Issue: 2792

Affects: dEQP-VK.wsi.*.full_screen_exclusive.*

Components: Vulkan
Change-Id: I7c970289769fd56c9f46ac27cc6d23180e847d74