Callback elision for HIDL interfaces.

Test: mma, hidl_test
Bug: 31380743
Change-Id: Ic5390d49a9493d1180bdd8a15bc47e891637890e
diff --git a/tests/bar/1.0/default/Bar.h b/tests/bar/1.0/default/Bar.h
index 70bffe7..b276823 100644
--- a/tests/bar/1.0/default/Bar.h
+++ b/tests/bar/1.0/default/Bar.h
@@ -71,8 +71,7 @@
 
     Return<void> takeAMask(BitField bf, uint8_t first, const MyMask& second, uint8_t third,
             takeAMask_cb _hidl_cb) override;
-    Return<void> haveAInterface(const sp<ISimple> &in,
-            haveAInterface_cb _hidl_cb) override;
+    Return<sp<ISimple>> haveAInterface(const sp<ISimple> &in);
 
 private:
     sp<IFoo> mFoo;