Fix the error spotted by meson

- This commit would fix the error that are spotted by meson
  when werror=true is enforced.

Tested By:

- Compiled in all the sdks, and unit tests are passed.

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: Ie4c2f26af2b62b019e908cceea18cf22cf2e4607
diff --git a/ncsi_util.cpp b/ncsi_util.cpp
index 2b3fb54..40d6379 100644
--- a/ncsi_util.cpp
+++ b/ncsi_util.cpp
@@ -27,7 +27,7 @@
 using nlMsgPtr = std::unique_ptr<nl_msg, decltype(&::nlmsg_free)>;
 using nlSocketPtr = std::unique_ptr<nl_sock, decltype(&::nl_socket_free)>;
 
-CallBack infoCallBack = [](struct nl_msg* msg, void* arg) {
+CallBack infoCallBack = [](struct nl_msg* msg, void* /*arg*/) {
     using namespace phosphor::network::ncsi;
     auto nlh = nlmsg_hdr(msg);