try! -> ?

Automated conversion using the untry tool [1] and the following command:

```
$ find -name '*.rs' -type f | xargs untry
```

at the root of the Rust repo.

[1]: https://github.com/japaric/untry

src/libstd/net/mod.rs

@@ -74,7 +74,7 @@ fn each_addr<A: ToSocketAddrs, F, T>(addr: A, mut f: F) -> io::Result<T>
     where F: FnMut(&SocketAddr) -> io::Result<T>
 {
     let mut last_err = None;
-    for addr in try!(addr.to_socket_addrs()) {
+    for addr in addr.to_socket_addrs()? {
         match f(&addr) {
             Ok(l) => return Ok(l),
             Err(e) => last_err = Some(e),