Fix extension checks in DRM format modifier tests

Some of the checks for supported extensions made the tests error out
instead of marking them as not supported.

Affected tests:
dEQP-VK.drm_format_modifiers.*

Components: Vulkan
VK-GL-CTS issue: 3720

Change-Id: I47c1f051128e425d5faae3bed5c2830218df4881
diff --git a/external/vulkancts/modules/vulkan/modifiers/vktModifiersTests.cpp b/external/vulkancts/modules/vulkan/modifiers/vktModifiersTests.cpp
index 1863b8d..8738f11 100644
--- a/external/vulkancts/modules/vulkan/modifiers/vktModifiersTests.cpp
+++ b/external/vulkancts/modules/vulkan/modifiers/vktModifiersTests.cpp
@@ -64,13 +64,13 @@
 		TCU_THROW(NotSupportedError, "VK_EXT_image_drm_format_modifier is not supported");
 
 	if (!context.isInstanceFunctionalitySupported("VK_KHR_get_physical_device_properties2"))
-		TCU_THROW(TestError, "VK_KHR_get_physical_device_properties2 not supported");
+		TCU_THROW(NotSupportedError, "VK_KHR_get_physical_device_properties2 not supported");
 
 	if (!context.isDeviceFunctionalitySupported("VK_KHR_bind_memory2"))
-		TCU_THROW(TestError, "VK_KHR_bind_memory2 not supported");
+		TCU_THROW(NotSupportedError, "VK_KHR_bind_memory2 not supported");
 
 	if (!context.isDeviceFunctionalitySupported("VK_KHR_image_format_list"))
-		TCU_THROW(TestError, "VK_KHR_image_format_list not supported");
+		TCU_THROW(NotSupportedError, "VK_KHR_image_format_list not supported");
 }
 
 void checkModifiersList2Supported (Context& context, VkFormat fmt)
@@ -78,7 +78,7 @@
 	checkModifiersSupported(context, fmt);
 
 	if (!context.isDeviceFunctionalitySupported("VK_KHR_format_feature_flags2"))
-		TCU_THROW(TestError, "VK_KHR_format_feature_flags2 not supported");
+		TCU_THROW(NotSupportedError, "VK_KHR_format_feature_flags2 not supported");
 }
 
 std::string getFormatCaseName (VkFormat format)