Improvements from clippy

common/src/io.rs

@@ -1,4 +1,4 @@
-use std::io::{Error, ErrorKind, Read, Write};
+use std::io::{Error, Read, Write};
 
 /// The saslauthd protocol transmits strings as
 /// 16-bit unsigned network-byte-order lengths followed
@@ -16,7 +16,7 @@ pub fn read_string(stream: &mut impl Read) -> Result<String, Error> {
 
     match String::from_utf8(string_buffer) {
         Ok(str) => Ok(str),
-        Err(_err) => Err(Error::new(ErrorKind::Other, "Invalid UTF-8 sent")),
+        Err(_err) => Err(Error::other("Invalid UTF-8 sent")),
     }
 }
 
@@ -24,7 +24,7 @@ pub fn write_string(stream: &mut impl Write, s: &str) -> Result<(), Error> {
     let length = s.len();
 
     if length > 0xffff {
-        return Err(Error::new(ErrorKind::Other, "String too long to write"));
+        return Err(Error::other("String too long to write"));
     }
 
     let length_buffer = [(length >> 8) as u8, (length & 0xff) as u8];