Update clang-tidy

Fix a bunch of minor issues, ignore others.  We use a lot of global
variables.  Enabling a check will hopefully make sure we don't add more.

Change-Id: Ie76053d4afc95a5372b70b2fb768be464468cec0
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/src/perform_scan.cpp b/src/perform_scan.cpp
index 5e5b715..c503d99 100644
--- a/src/perform_scan.cpp
+++ b/src/perform_scan.cpp
@@ -24,11 +24,13 @@
 #include <charconv>
 
 /* Hacks from splitting entity_manager.cpp */
+// NOLINTBEGIN(cppcoreguidelines-avoid-non-const-global-variables)
 extern std::shared_ptr<sdbusplus::asio::connection> systemBus;
 extern nlohmann::json lastJson;
 extern void
     propertiesChangedCallback(nlohmann::json& systemConfiguration,
                               sdbusplus::asio::object_server& objServer);
+// NOLINTEND(cppcoreguidelines-avoid-non-const-global-variables)
 
 using GetSubTreeType = std::vector<
     std::pair<std::string,