Correct merge failure around imports in str.rs.

Author: nikomatsakis

src/libcore/str.rs

@@ -30,10 +30,9 @@ use iter::range;
 use kinds::Sized;
 use mem;
 use num::Int;
-use ops::FnMut;
+use ops::{Fn, FnMut};
 use option::Option;
 use option::Option::{None, Some};
-use ops::{Fn, FnMut};
 use ptr::RawPtr;
 use raw::{Repr, Slice};
 use slice::{mod, SliceExt};