Fix some issues for Linux Vulkan build

lifecycle in GrVkGpu was tagged as uninitialized before use, and err in GrVkImage as unused.

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1782453004

Review URL: https://codereview.chromium.org/1782453004
diff --git a/src/gpu/vk/GrVkImage.cpp b/src/gpu/vk/GrVkImage.cpp
index a87a7a5..a61d934 100644
--- a/src/gpu/vk/GrVkImage.cpp
+++ b/src/gpu/vk/GrVkImage.cpp
@@ -49,8 +49,6 @@
     VkImage image = 0;
     VkDeviceMemory alloc;
 
-    VkResult err;
-
     VkImageLayout initialLayout = (VK_IMAGE_TILING_LINEAR == imageDesc.fImageTiling)
         ? VK_IMAGE_LAYOUT_PREINITIALIZED
         : VK_IMAGE_LAYOUT_UNDEFINED;
@@ -78,8 +76,7 @@
         initialLayout                                // initialLayout
     };
 
-    err = VK_CALL(gpu, CreateImage(gpu->device(), &imageCreateInfo, nullptr, &image));
-    SkASSERT(!err);
+    GR_VK_CALL_ERRCHECK(gpu->vkInterface(), CreateImage(gpu->device(), &imageCreateInfo, nullptr, &image));
 
     if (!GrVkMemory::AllocAndBindImageMemory(gpu, image, imageDesc.fMemProps, &alloc)) {
         VK_CALL(gpu, DestroyImage(gpu->device(), image, nullptr));
@@ -115,4 +112,4 @@
 void GrVkImage::Resource::freeGPUData(const GrVkGpu* gpu) const {
     VK_CALL(gpu, DestroyImage(gpu->device(), fImage, nullptr));
     VK_CALL(gpu, FreeMemory(gpu->device(), fAlloc, nullptr));
-}
\ No newline at end of file
+}