Remove workaround for pub extern crate

On semi-recent Rust versions (I think 1.8+) this now works properly.

Author: jonas-schievink

src/lib.rs

@@ -23,13 +23,7 @@ extern crate nix_test as nixtest;
 
 #[macro_use] mod macros;
 
-// In rust 1.8+ this should be `pub extern crate libc` but prior
-// to https://github.com/rust-lang/rust/issues/26775 being resolved
-// it is necessary to get a little creative.
-pub mod libc {
-    extern crate libc;
-    pub use self::libc::*;
-}
+pub extern crate libc;
 
 pub use libc::{c_int, c_void};
 pub use errno::Errno;