Fix formatting for ref_mut_iter_method_chain

Author: Jarcho

clippy_lints/src/methods/ref_mut_iter_method_chain.rs

@@ -17,7 +17,8 @@ pub(crate) fn check(cx: &LateContext<'_>, self_arg: &Expr<'_>) {
         if implements_trait(cx, cx.typeck_results().expr_ty(base_expr).peel_refs(), iter_trait, &[]);
         then {
             let snip_expr = match base_expr.kind {
-                ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() && !base_expr.span.from_expansion()
+                ExprKind::Unary(UnOp::Deref, e)
+                if cx.typeck_results().expr_ty(e).is_ref() && !base_expr.span.from_expansion()
                     => e,
                 _ => base_expr,
             };