Remove trailing space in error message

compiler/rustc_middle/src/ty/error.rs

@@ -232,7 +232,7 @@ impl<'tcx> ty::TyS<'tcx> {
                 let n = tcx.lift(&n).unwrap();
                 match n.try_eval_usize(tcx, ty::ParamEnv::empty()) {
                     _ if t.is_simple_ty() => format!("array `{}`", self).into(),
-                    Some(n) => format!("array of {} element{} ", n, pluralize!(n)).into(),
+                    Some(n) => format!("array of {} element{}", n, pluralize!(n)).into(),
                     None => "array".into(),
                 }
             }

src/test/ui/slice-to-vec-comparison.stderr

@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/slice-to-vec-comparison.rs:4:9
    |
 LL |     a > b;
-   |         ^ expected array of 0 elements , found struct `Vec`
+   |         ^ expected array of 0 elements, found struct `Vec`
    |
    = note: expected reference `&[_; 0]`
               found reference `&Vec<u8>`