Remove more redundant code

Author: jonas-schievink

src/sys/socket/mod.rs

@@ -602,27 +602,19 @@ impl<'a> ControlMessage<'a> {
             };
             let buf = copy_bytes(&cmsg, buf);
 
+            let padlen = cmsg_align(mem::size_of_val(&cmsg)) -
+                mem::size_of_val(&cmsg);
+            let buf = pad_bytes(padlen, buf);
+
             match *self {
                 ControlMessage::ScmRights(fds) => {
-                    let padlen = cmsg_align(mem::size_of_val(&cmsg)) -
-                        mem::size_of_val(&cmsg);
-                    let buf = pad_bytes(padlen, buf);
-
                     copy_bytes(fds, buf)
                 },
                 #[cfg(any(target_os = "android", target_os = "linux"))]
                 ControlMessage::ScmCredentials(creds) => {
-                    let padlen = cmsg_align(mem::size_of_val(&cmsg)) -
-                        mem::size_of_val(&cmsg);
-                    let buf = pad_bytes(padlen, buf);
-
                     copy_bytes(creds, buf)
                 }
                 ControlMessage::ScmTimestamp(t) => {
-                    let padlen = cmsg_align(mem::size_of_val(&cmsg)) -
-                        mem::size_of_val(&cmsg);
-                    let buf = pad_bytes(padlen, buf);
-
                     copy_bytes(t, buf)
                 },
                 ControlMessage::Unknown(_) => unreachable!(),