Tutorial 9. Texture::load() return type fix

docs/beginner/tutorial9-models/README.md

@@ -127,7 +127,7 @@ pub fn load<P: AsRef<Path>>(
     device: &wgpu::Device,
     queue: &wgpu::Queue,
     path: P,
-) -> Result<(Self, wgpu::CommandBuffer), failure::Error> {
+) -> Result<Self> {
     // Needed to appease the borrow checker
     let path_copy = path.as_ref().to_path_buf();
     let label = path_copy.to_str();