Tweak test.

tests/ui/collapsible_span_lint_calls.rs

@@ -14,6 +14,7 @@ use rustc_lint::{EarlyContext, EarlyLintPass, LintContext, Lint};
 use syntax::ast::Expr;
 use rustc_span::source_map::Span;
 
+#[allow(unused_variables)]
 pub fn span_lint_and_then<'a, T: LintContext, F>(cx: &'a T, lint: &'static Lint, sp: Span, msg: &str, f: F)
 where
     F: for<'b> FnOnce(&mut DiagnosticBuilder<'b>),
@@ -35,6 +36,7 @@ impl EarlyLintPass for Pass {
         let help_msg = "help message";
         let note_msg = "note message";
         let sugg = "new_call()";
+
         span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db| {
             db.span_suggestion(expr.span, help_msg, sugg.to_string(), Applicability::MachineApplicable);
         });