binder_ndk: fix performance-unnecessary-value-param

Bug: 162909698
Test: m libbinder

Change-Id: I89779ab38a28972c1ad15733aff34a51e7e7fa8a
diff --git a/libs/binder/ndk/ibinder_internal.h b/libs/binder/ndk/ibinder_internal.h
index 0fa47c6..6236e81 100644
--- a/libs/binder/ndk/ibinder_internal.h
+++ b/libs/binder/ndk/ibinder_internal.h
@@ -161,8 +161,8 @@
     };
 
     explicit AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied);
-    binder_status_t linkToDeath(::android::sp<::android::IBinder>, void* cookie);
-    binder_status_t unlinkToDeath(::android::sp<::android::IBinder> binder, void* cookie);
+    binder_status_t linkToDeath(const ::android::sp<::android::IBinder>&, void* cookie);
+    binder_status_t unlinkToDeath(const ::android::sp<::android::IBinder>& binder, void* cookie);
 
    private:
     // When the user of this API deletes a Bp object but not the death recipient, the