Make code compile with clang-13

Clang-13 rightfully warns that the hasWebuiRoute variable isn't declared
as static.  This commit resolves that, and adds the static keyword so it
can be used in multiple compile units.  It also adds the static keyword
to the privilege registry, and the inline keyword to many methods that
now need it.

clang-format is also updated to version 12 in parse_registies.py, as
that's what CI uses, and what most people have installed.

Tested:
Followed clang-tidy instructions in README.md
"bitbake bmcweb" step now succeeds.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Id43b13606754cb37a404799fce155599ac3a3240
diff --git a/redfish-core/lib/systems.hpp b/redfish-core/lib/systems.hpp
index 2b9636f..45a3249 100644
--- a/redfish-core/lib/systems.hpp
+++ b/redfish-core/lib/systems.hpp
@@ -2223,7 +2223,7 @@
     BMCWEB_ROUTE(app, "/redfish/v1/Systems/")
         .privileges(redfish::privileges::getComputerSystemCollection)
         .methods(boost::beast::http::verb::get)(
-            [](const crow::Request& req,
+            [](const crow::Request& /*req*/,
                const std::shared_ptr<bmcweb::AsyncResp>& asyncResp) {
                 asyncResp->res.jsonValue["@odata.type"] =
                     "#ComputerSystemCollection.ComputerSystemCollection";
@@ -2231,9 +2231,8 @@
                 asyncResp->res.jsonValue["Name"] = "Computer System Collection";
 
                 crow::connections::systemBus->async_method_call(
-                    [asyncResp,
-                     &req](const boost::system::error_code ec,
-                           const std::variant<std::string>& /*hostName*/) {
+                    [asyncResp](const boost::system::error_code ec,
+                                const std::variant<std::string>& /*hostName*/) {
                         nlohmann::json& ifaceArray =
                             asyncResp->res.jsonValue["Members"];
                         ifaceArray = nlohmann::json::array();
@@ -2262,7 +2261,7 @@
 /**
  * Function transceives data with dbus directly.
  */
-void doNMI(const std::shared_ptr<bmcweb::AsyncResp>& asyncResp)
+inline void doNMI(const std::shared_ptr<bmcweb::AsyncResp>& asyncResp)
 {
     constexpr char const* serviceName = "xyz.openbmc_project.Control.Host.NMI";
     constexpr char const* objectPath = "/xyz/openbmc_project/control/host0/nmi";