tests: Make image object init robust to failure

Added early return to VkImageObj::Init s.t. image handle creation
failure wouldn't lead to application failure.

Change-Id: Ia873334032b428693d52a1070ecd5b4d845e9657
diff --git a/tests/vkrenderframework.cpp b/tests/vkrenderframework.cpp
index 8dbd1ee..5119f70 100644
--- a/tests/vkrenderframework.cpp
+++ b/tests/vkrenderframework.cpp
@@ -957,6 +957,8 @@
                       const std::vector<uint32_t> *queue_families) {
     InitNoLayout(width, height, mipLevels, format, usage, requested_tiling, reqs, queue_families);
 
+    if (!initialized()) return;  // We don't have a valid handle from early stage init, and thus SetLayout will fail
+
     VkImageLayout newLayout;
     if (usage & VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT)
         newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;