Resolve needless_borrow clippy lint

    error: this expression borrows a reference (`&syn::parse::ParseBuffer`) that is immediately dereferenced by the compiler
      --> tests/test_parse_buffer.rs:15:35
       |
    15 |                 input1.advance_to(&input2);
       |                                   ^^^^^^^ help: change this to: `input2`
       |
       = note: `-D clippy::needless-borrow` implied by `-D clippy::all`
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

tests/test_parse_buffer.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::needless_borrow, clippy::non_ascii_literal)]
+#![allow(clippy::non_ascii_literal)]
 
 use proc_macro2::{Delimiter, Group, Punct, Spacing, TokenStream, TokenTree};
 use std::iter::FromIterator;
@@ -12,7 +12,7 @@ fn smuggled_speculative_cursor_between_sources() {
     impl Parse for BreakRules {
         fn parse(input1: ParseStream) -> Result<Self> {
             let nested = |input2: ParseStream| {
-                input1.advance_to(&input2);
+                input1.advance_to(input2);
                 Ok(Self)
             };
             nested.parse_str("")