core: Fix TestEvalWriteStateDeposed

This was already updated for the new state types earlier, but since then
we adjusted how deposed instances are written out in the old string
representation of state, and so this regressed.

terraform/eval_state_test.go

@@ -272,6 +272,6 @@ func TestEvalWriteStateDeposed(t *testing.T) {
 aws_instance.foo: (1 deposed)
   ID = <not created>
   provider = provider.aws
-  Deposed ID deadbeef = i-abc123
+  Deposed ID 1 = i-abc123
 	`)
 }