Fix nits for BinderUtil.h

Bug: 65862741
Test: built, flashed, booted
      system/netd/tests/runtests.sh pass

Change-Id: I0ac86d5b27360192aed2332f30515d7b4f01dc74
diff --git a/include/BinderUtil.h b/include/BinderUtil.h
index b14d440..9333dcd 100644
--- a/include/BinderUtil.h
+++ b/include/BinderUtil.h
@@ -56,7 +56,7 @@
 
 using LogFn = std::function<void(const std::string& msg)>;
 
-void binderCallLogFn(const Json::Value& logTransaction, LogFn logFn) {
+void binderCallLogFn(const Json::Value& logTransaction, const LogFn& logFn) {
     using namespace std::string_literals;
 
     bool hasReturnArgs;