Fixed multiple clippy warnings.

src/dns/netutil.rs

@@ -3,7 +3,7 @@ use std::net::TcpStream;
 
 pub fn read_packet_length(stream: &mut TcpStream) -> Result<u16> {
     let mut len_buffer = [0; 2];
-    stream.read(&mut len_buffer)?;
+    stream.read_exact(&mut len_buffer)?;
 
     Ok(((len_buffer[0] as u16) << 8) | (len_buffer[1] as u16))
 }
@@ -13,7 +13,7 @@ pub fn write_packet_length(stream: &mut TcpStream, len: usize) -> Result<()> {
     len_buffer[0] = (len >> 8) as u8;
     len_buffer[1] = (len & 0xFF) as u8;
 
-    stream.write(&len_buffer)?;
+    stream.write_all(&len_buffer)?;
 
     Ok(())
 }