Correct needless_borrow_for_generic_args doc comment (#15440)

I think the comment is meant to refer to `needless_borrow_count`.

changelog: none

Author: blyxyas

clippy_lints/src/needless_borrows_for_generic_args.rs

@@ -59,7 +59,7 @@ declare_clippy_lint! {
 
 pub struct NeedlessBorrowsForGenericArgs<'tcx> {
     /// Stack of (body owner, `PossibleBorrowerMap`) pairs. Used by
-    /// `needless_borrow_impl_arg_position` to determine when a borrowed expression can instead
+    /// [`needless_borrow_count`] to determine when a borrowed expression can instead
     /// be moved.
     possible_borrowers: Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>,