Add missing buffer features check in image store tests

Check if format supports storage write for VkBufferView where
OpTypeImage is Unknown

Components: Vulkan

VK-GL-CTS issue: 3765

Affected tests:
dEQP-VK.image.store.without_format.*

Change-Id: I74365f2f753fb61397d83403098a288cdcf53953
diff --git a/external/vulkancts/modules/vulkan/image/vktImageLoadStoreTests.cpp b/external/vulkancts/modules/vulkan/image/vktImageLoadStoreTests.cpp
index f6f844d..af0661c 100644
--- a/external/vulkancts/modules/vulkan/image/vktImageLoadStoreTests.cpp
+++ b/external/vulkancts/modules/vulkan/image/vktImageLoadStoreTests.cpp
@@ -486,6 +486,9 @@
 {
 	const VkFormatProperties3KHR formatProperties (context.getFormatProperties(m_format));
 
+	if (!m_declareImageFormatInShader && !(formatProperties.bufferFeatures & VK_FORMAT_FEATURE_2_STORAGE_WRITE_WITHOUT_FORMAT_BIT_KHR))
+		TCU_THROW(NotSupportedError, "Format not supported for unformatted stores via storage buffer");
+
 	if (!m_declareImageFormatInShader && !(formatProperties.optimalTilingFeatures & VK_FORMAT_FEATURE_2_STORAGE_WRITE_WITHOUT_FORMAT_BIT_KHR))
 		TCU_THROW(NotSupportedError, "Format not supported for unformatted stores via storage images");