Removed newlib struct duplicates.

Author: ischeinkman

src/unix/newlib/mod.rs

@@ -25,15 +25,6 @@ pub type time_t = i32;
 pub type useconds_t = u32;
 
 s! {
-    pub struct in_addr {
-        pub s_addr: ::in_addr_t,
-    }
-
-    pub struct ip_mreq {
-        pub imr_multiaddr: in_addr,
-        pub imr_interface: in_addr,
-    }
-
     pub struct sockaddr {
         pub sa_family: sa_family_t,
         pub sa_data: [::c_char; 14],