Combine thread use statement with previous

ahcid/src/ahci/hba.rs

@@ -1,7 +1,6 @@
 use std::mem::size_of;
 use std::ops::DerefMut;
-use std::{ptr, u32};
-use std::thread;
+use std::{ptr, u32, thread};
 
 use syscall::io::{Dma, Io, Mmio};
 use syscall::error::{Error, Result, EIO};