Merge pull request #538 from zahash/surface_format

use find() instead of filter().next()

docs/beginner/tutorial2-surface/README.md

@@ -164,9 +164,8 @@ The `limits` field describes the limit of certain types of resources that we can
         // one will result in all the colors coming out darker. If you want to support non
         // sRGB surfaces, you'll need to account for that when drawing to the frame.
         let surface_format = surface_caps.formats.iter()
+            .find(|f| f.is_srgb())
             .copied()
-            .filter(|f| f.is_srgb())
-            .next()
             .unwrap_or(surface_caps.formats[0]);
         let config = wgpu::SurfaceConfiguration {
             usage: wgpu::TextureUsages::RENDER_ATTACHMENT,