meson support: remove code warnings 2

This commit contains code changes necessary to support the increased
warning level from Meson builds. Most changes are for unused variables.
to keep the review size manageable, this commit contains only control
changes (plus one in sensor-monitor).

Change-Id: Ie20f1d9028add4b605e4cc9fb230940710365706
Signed-off-by: Mike Capps <mikepcapps@gmail.com>
diff --git a/control/json/triggers/parameter.cpp b/control/json/triggers/parameter.cpp
index 3abe57c..6f4eac3 100644
--- a/control/json/triggers/parameter.cpp
+++ b/control/json/triggers/parameter.cpp
@@ -26,7 +26,7 @@
 
 enableTrigger
     triggerParameter(const json& jsonObj, const std::string& eventName,
-                     std::vector<std::unique_ptr<ActionBase>>& actions)
+                     std::vector<std::unique_ptr<ActionBase>>& /*actions*/)
 {
     if (!jsonObj.contains("parameter"))
     {
@@ -38,8 +38,8 @@
 
     auto name = jsonObj["parameter"].get<std::string>();
 
-    return [name](const std::string& eventName, Manager* mgr,
-                  const std::vector<Group>& groups,
+    return [name](const std::string& /*eventName*/, Manager* /*mgr*/,
+                  const std::vector<Group>& /*groups*/,
                   std::vector<std::unique_ptr<ActionBase>>& actions) {
         Manager::addParameterTrigger(name, actions);
     };