vulkan/wsi/x11: Consistently update and return swapchain status

vulkan/wsi/x11: Consistently update and return swapchain status

Use a helper function for updating the swapchain status. This will be
used later to handle VK_SUBOPTIMAL_KHR, where we need to make a
non-error status stick to the swapchain until recreation.  Instead of
direct comparisons to VK_SUCCESS to check for error, test for negative
numbers meaning an error status, and positive numbers indicating
non-error statuses.

v2 (Jason Ekstrand):
 - Use a pattern of "return x11_swapchain_result(chain, VK_WHATEVER)"
 - Handle wsi_queue_pull returning VK_TIMEOUT
 - Call x11_swapchain_result in x11_present_to_x11

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>