Make vktPipelineRenderToImageTests.cpp identical with upstream

I accidentally introduced a code change in c15f596c3 (Revert "[Fuchsia]
Workaround for max pinnable buffer size", 2021-10-12).

Change-Id: I15038aa4bb67b48eb7bbe98b4f9b684d7d92f359
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/vulkan-cts/+/593606
Reviewed-by: Craig Stout <cstout@google.com>
diff --git a/external/vulkancts/modules/vulkan/pipeline/vktPipelineRenderToImageTests.cpp b/external/vulkancts/modules/vulkan/pipeline/vktPipelineRenderToImageTests.cpp
index a4929b6..a13b8df 100644
--- a/external/vulkancts/modules/vulkan/pipeline/vktPipelineRenderToImageTests.cpp
+++ b/external/vulkancts/modules/vulkan/pipeline/vktPipelineRenderToImageTests.cpp
@@ -899,6 +899,10 @@
 	VkDeviceSize					neededMemory		= static_cast<VkDeviceSize>(static_cast<float>(colorSize + depthStencilSize) * additionalMemory) + reserveForChecking;
 	VkDeviceSize					maxMemory			= getMaxDeviceHeapSize(context, caseDef) >> 2;
 
+	vk::PlatformMemoryLimits		memoryLimits;
+	context.getTestContext().getPlatform().getVulkanPlatform().getMemoryLimits(memoryLimits);
+	maxMemory = std::min(maxMemory, VkDeviceSize(memoryLimits.totalSystemMemory));
+
 	const VkDeviceSize				deviceMemoryBudget	= std::min(neededMemory, maxMemory);
 	bool							allocationPossible	= false;