rust: allow some clippy lints without warning

Suppresses some clippy lints that have more to do with style
than anything else, to reduce the amount of noise in the
clippy output.

rust/src/lib.rs

@@ -17,6 +17,13 @@
 
 #![cfg_attr(feature = "strict", deny(warnings))]
 
+// Clippy lints we want to suppress due to style, or simply too noisy
+// and not a priority right now.
+#![allow(clippy::missing_safety_doc)]
+#![allow(clippy::needless_return)]
+#![allow(clippy::redundant_field_names)]
+#![allow(clippy::len_zero)]
+
 #[macro_use]
 extern crate nom;