Fix for dEQP-VK.wsi.*.swapchain.acquire.too_many_timeout

With the assertion for these tests fixed here:
https://gerrit.khronos.org/#/c/6075/

The *.too_many test passed locally, but not the *.too_many_timeout
test. The reason is that, when a timeout is provided, the acceptable
return value for failing to acquire an image is VK_TIMEOUT, not
VK_NOT_READY. Returning VK_TIMEOUT when a timeout is provided solves
the issue.

Bug: b/162249856
Change-Id: Id2733fec8422aad93a1aa351b481691c69692168
Tests: dEQP-VK.wsi.*.swapchain.acquire.*
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/47648
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
diff --git a/src/WSI/VkSwapchainKHR.cpp b/src/WSI/VkSwapchainKHR.cpp
index 6440ab1..aed8c03 100644
--- a/src/WSI/VkSwapchainKHR.cpp
+++ b/src/WSI/VkSwapchainKHR.cpp
@@ -194,7 +194,7 @@
 		}
 	}
 
-	return VK_NOT_READY;
+	return (timeout > 0) ? VK_TIMEOUT : VK_NOT_READY;
 }
 
 VkResult SwapchainKHR::present(uint32_t index)