Fix empty_test lint pass import

Author: willwang-io

clippy_lints/src/empty_test.rs

@@ -2,8 +2,7 @@ use clippy_utils::diagnostics::span_lint;
 use clippy_utils::is_test_function;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{Body, ExprKind, FnDecl};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::declare_lint_pass;
+use rustc_lint::{LateContext, LateLintPass, declare_lint_pass};
 use rustc_span::Span;
 use rustc_span::def_id::LocalDefId;
 

tests/ui/empty_test.stderr

@@ -16,4 +16,3 @@ LL | | }
    | |_^
 
 error: aborting due to 2 previous errors
-