rust(lint): map the error instead of using or_else

This is the preffered style and easier to understand the meaning
of the code.

diff --git a/rust/src/dns/detect.rs b/rust/src/dns/detect.rs
index 326e9c38a714dc2fcfde073438c4c608850fa91f..b389d2c57f11db43dd7baa6a21570552f0342068 100644 (file)
--- a/rust/src/dns/detect.rs
+++ b/rust/src/dns/detect.rs
@@ -42,7 +42,7 @@ fn parse_opcode(opcode: &str) -> Result<DetectDnsOpcode, ()> {
                 negated = true;
             }
             _ => {
-                let code: u8 = (&opcode[i..]).parse().or_else(|_| Err(()))?;
+                let code: u8 = (&opcode[i..]).parse().map_err(|_| ())?;
                 return Ok(DetectDnsOpcode {
                     negate: negated,
                     opcode: code,