Out out of unhelpful clippy lint

Author: Shnatsel

cargo-auditable/src/rustc_wrapper.rs

@@ -68,6 +68,7 @@ fn rustc_command_with_audit_data(rustc_path: &OsStr) -> Option<Command> {
     //
     // Binaries and C dynamic libraries are not built as non-primary packages,
     // so this should not cause issues with Cargo caches.
+    #[allow(clippy::question_mark)]
     if env::var_os("CARGO_PRIMARY_PACKAGE").is_none() {
         return None;
     }