Merge branch 'usleep' into 'master'

Fix usleep

Closes #144

See merge request redox-os/relibc!204

src/header/unistd/mod.rs

@@ -666,7 +666,7 @@ pub unsafe extern "C" fn unlink(path: *const c_char) -> c_int {
 pub extern "C" fn usleep(useconds: useconds_t) -> c_int {
     let rqtp = timespec {
         tv_sec: (useconds / 1_000_000) as i64,
-        tv_nsec: ((useconds % 1000) * 1000) as i64,
+        tv_nsec: ((useconds % 1_000_000) * 1000) as i64,
     };
     let rmtp = ptr::null_mut();
     Sys::nanosleep(&rqtp, rmtp)