Changed the lint group to complexity

Author: theo-lw

clippy_lints/src/map_identity.rs

@@ -27,7 +27,7 @@ declare_clippy_lint! {
     /// let y: Vec<_> = x.iter().map(|x| 2*x).collect();
     /// ```
     pub MAP_IDENTITY,
-    style,
+    complexity,
     "using iterator.map(|x| x)"
 }