Fix return from nullptr to false in GrVkTexture.cpp

src/gpu/vk/GrVkTexture.cpp

Index: src/gpu/vk/GrVkTexture.cpp
diff --git a/src/gpu/vk/GrVkTexture.cpp b/src/gpu/vk/GrVkTexture.cpp
index fef6b7292847045ce69267a085021a54d4df8536..62cb3dfc3a1413f7e8b8c3ec8d998610523ab0db 100644
--- a/src/gpu/vk/GrVkTexture.cpp
+++ b/src/gpu/vk/GrVkTexture.cpp
@@ -196,7 +196,7 @@ bool GrVkTexture::reallocForMipmap(const GrVkGpu* gpu, uint32_t mipLevels) {
 
     GrVkImageInfo info;
     if (!GrVkImage::InitImageInfo(gpu, imageDesc, &info)) {
-        return nullptr;
+        return false;
     }
 
     // have to create a new image view for new resource