Don't override vkQueuePresentKHR() failure codes with VK_SUBOPTIMAL_KHR

VK_SUBOPTIMAL_KHR is a success code so it should not override failure
codes, but should not get replaced by a VK_SUCCESS result itself.

Bug: b/144766511
Change-Id: Ie7721fb3afc36f0b15579deff79dc9bdc9146cd0
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/40308
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Vulkan/VkQueue.cpp

diff --git a/src/Vulkan/VkQueue.cpp b/src/Vulkan/VkQueue.cpp
index f4703e9..136eafd 100644
--- a/src/Vulkan/VkQueue.cpp
+++ b/src/Vulkan/VkQueue.cpp
@@ -235,9 +235,14 @@
 			presentInfo->pResults[i] = perSwapchainResult;
 		}
 
+		// Keep track of the worst result code. VK_SUBOPTIMAL_KHR is a success code so it should
+		// not override failure codes, but should not get replaced by a VK_SUCCESS result itself.
 		if(perSwapchainResult != VK_SUCCESS)
 		{
-			commandResult = perSwapchainResult;
+			if(commandResult == VK_SUCCESS || commandResult == VK_SUBOPTIMAL_KHR)
+			{
+				commandResult = perSwapchainResult;
+			}
 		}
 	}