std: Fix build errors

src/libstd/io/net/tcp.rs

@@ -109,7 +109,7 @@ impl TcpStream {
     pub fn connect_timeout(addr: SocketAddr,
                            timeout: Duration) -> IoResult<TcpStream> {
         if timeout <= Duration::milliseconds(0) {
-            return standard_error(TimedOut);
+            return Err(standard_error(TimedOut));
         }
 
         let SocketAddr { ip, port } = addr;

src/libstd/io/net/unix.rs

@@ -75,7 +75,7 @@ impl UnixStream {
     pub fn connect_timeout<P: ToCStr>(path: &P,
                                       timeout: Duration) -> IoResult<UnixStream> {
         if timeout <= Duration::milliseconds(0) {
-            return standard_error(TimedOut);
+            return Err(standard_error(TimedOut));
         }
 
         LocalIo::maybe_raise(|io| {

src/libstd/time/duration.rs

@@ -16,7 +16,7 @@ use {fmt, i32};
 use ops::{Add, Sub, Mul, Div, Neg};
 use option::{Option, Some, None};
 use num;
-use num::{CheckedAdd, CheckedMul, ToPrimitive};
+use num::{CheckedAdd, CheckedMul};
 use result::{Result, Ok, Err};