std: minor whitespace cleanup

Author: erickt

src/libstd/prelude.rs

@@ -62,7 +62,7 @@ pub use tuple::{Tuple1, Tuple2, Tuple3, Tuple4};
 pub use tuple::{Tuple5, Tuple6, Tuple7, Tuple8};
 pub use tuple::{Tuple9, Tuple10, Tuple11, Tuple12};
 pub use vec::{ImmutableEqVector, ImmutableTotalOrdVector, ImmutableCloneableVector};
-pub use vec::{OwnedVector, OwnedCloneableVector,OwnedEqVector};
+pub use vec::{OwnedVector, OwnedCloneableVector, OwnedEqVector};
 pub use vec::{MutableVector, MutableTotalOrdVector};
 pub use vec::{Vector, VectorVector, CloneableVector, ImmutableVector};