Lots of little cleanup improvements to Vulkan

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2336763002

Review-Url: https://codereview.chromium.org/2336763002
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index ed165c5..a339377 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -1570,6 +1570,7 @@
                             const SkIPoint& dstPoint) {
     if (can_copy_as_resolve(dst, src, this)) {
         this->copySurfaceAsResolve(dst, src, srcRect, dstPoint);
+        return true;
     }
 
     GrVkImage* dstImage;