Skip formats not supported by mapVkFormat in mismatchedFormatsTests

Skip formats which will throw InternalError in the mapVkFormat function

VK-GL-CTS issue: 4557

Components: Vulkan

Affected tests:
None

Change-Id: I1b847340af7b06867a13a649208d7b931266f7be
diff --git a/external/vulkancts/modules/vulkan/image/vktImageMismatchedFormatsTests.cpp b/external/vulkancts/modules/vulkan/image/vktImageMismatchedFormatsTests.cpp
index ae248f8..6627db0 100644
--- a/external/vulkancts/modules/vulkan/image/vktImageMismatchedFormatsTests.cpp
+++ b/external/vulkancts/modules/vulkan/image/vktImageMismatchedFormatsTests.cpp
@@ -459,6 +459,9 @@
 
 	for (VkFormat format = VK_FORMAT_R4G4_UNORM_PACK8; format < VK_CORE_FORMAT_LAST; format = static_cast<VkFormat>(format+1))
 	{
+		if (isCompressedFormat(format))
+			continue;
+
 		for (auto& pair : SpirvFormats)
 		{
 			const std::string&	spirvFormat = pair.first;