Fix build

Author: gnzlbg

src/mismatch.rs

@@ -10,7 +10,7 @@ use rustc::{
     hir::def_id::DefId,
     ty::{
         self,
-        relate::{Relate, RelateResult, TraitObjectMode, TypeRelation},
+        relate::{Relate, RelateResult, TypeRelation},
         subst::Substs,
         Ty, TyCtxt,
         Visibility::Public,
@@ -95,10 +95,6 @@ impl<'a, 'gcx, 'tcx> TypeRelation<'a, 'gcx, 'tcx> for MismatchRelation<'a, 'gcx,
         "Mismatch"
     }
 
-    fn trait_object_mode(&self) -> TraitObjectMode {
-        TraitObjectMode::NoSquash
-    }
-
     fn a_is_expected(&self) -> bool {
         true
     }