Remove redundant conversions.

Author: sunfishcode

library/std/src/os/unix/net/listener.rs

@@ -274,15 +274,15 @@ impl AsFd for UnixListener {
 impl From<OwnedFd> for UnixListener {
     #[inline]
     fn from(fd: OwnedFd) -> UnixListener {
-        UnixListener(Socket::from_inner(FromInner::from_inner(OwnedFd::from(fd))))
+        UnixListener(Socket::from_inner(FromInner::from_inner(fd)))
     }
 }
 
 #[unstable(feature = "io_safety", issue = "87074")]
 impl From<UnixListener> for OwnedFd {
     #[inline]
     fn from(listener: UnixListener) -> OwnedFd {
-        listener.0.into_inner().into_inner().into()
+        listener.0.into_inner().into_inner()
     }
 }