Fix return from nullptr to false in GrVkTexture.cpp

TBR=egdaniel@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1978113002

Review-Url: https://codereview.chromium.org/1978113002
diff --git a/src/gpu/vk/GrVkTexture.cpp b/src/gpu/vk/GrVkTexture.cpp
index fef6b72..62cb3df 100644
--- a/src/gpu/vk/GrVkTexture.cpp
+++ b/src/gpu/vk/GrVkTexture.cpp
@@ -196,7 +196,7 @@
 
     GrVkImageInfo info;
     if (!GrVkImage::InitImageInfo(gpu, imageDesc, &info)) {
-        return nullptr;
+        return false;
     }
 
     // have to create a new image view for new resource