Use () for entry_fn.

Author: cjgillot

clippy_utils/src/lib.rs

@@ -60,7 +60,7 @@ use rustc_ast::ast::{self, Attribute, BorrowKind, LitKind};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{self, walk_expr, ErasedMap, FnKind, NestedVisitorMap, Visitor};
 use rustc_hir::LangItem::{ResultErr, ResultOk};
 use rustc_hir::{
@@ -677,7 +677,7 @@ pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option<Vec
 /// Returns `true` if the provided `def_id` is an entrypoint to a program.
 pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool {
     cx.tcx
-        .entry_fn(LOCAL_CRATE)
+        .entry_fn(())
         .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id)
 }