remove usage of sdbusplus::message::variant

sdbusplus has had its alias of std::variant in place for long
enough. This changes all ipmid references to use std::variant
directly instead of the sdbusplus alias.

Tested-by: building and running ipmid

Change-Id: Id5b4136d4589aa598815edd3ef4202e64a7698e2
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/chassishandler.cpp b/chassishandler.cpp
index a9e188f..541ab52 100644
--- a/chassishandler.cpp
+++ b/chassishandler.cpp
@@ -1139,7 +1139,7 @@
         dbus.new_method_call(connection.c_str(), identify_led_object_name,
                              "org.freedesktop.DBus.Properties", "Set");
     led.append("xyz.openbmc_project.Led.Group", "Asserted",
-               sdbusplus::message::variant<bool>(flag));
+               std::variant<bool>(flag));
     auto ledReply = dbus.call(led);
     if (ledReply.is_method_error())
     {
@@ -1251,8 +1251,7 @@
 {
     using namespace chassis::internal;
     using namespace chassis::internal::cache;
-    sdbusplus::message::variant<std::string> property =
-        convertForMessage(source);
+    std::variant<std::string> property = convertForMessage(source);
     auto bootSetting = settings::boot::setting(objects, bootSourceIntf);
     const auto& bootSourceSetting = std::get<settings::Path>(bootSetting);
     auto method = dbus.new_method_call(
@@ -1277,7 +1276,7 @@
 {
     using namespace chassis::internal;
     using namespace chassis::internal::cache;
-    sdbusplus::message::variant<std::string> property = convertForMessage(mode);
+    std::variant<std::string> property = convertForMessage(mode);
     auto bootSetting = settings::boot::setting(objects, bootModeIntf);
     const auto& bootModeSetting = std::get<settings::Path>(bootSetting);
     auto method = dbus.new_method_call(
@@ -1344,7 +1343,7 @@
                 *data_len = 0;
                 return IPMI_CC_UNSPECIFIED_ERROR;
             }
-            sdbusplus::message::variant<std::string> result;
+            std::variant<std::string> result;
             reply.read(result);
             auto bootSource =
                 Source::convertSourcesFromString(std::get<std::string>(result));
@@ -1644,8 +1643,7 @@
             chassis::internal::cache::objects.map
                 .at(chassis::internal::powerRestoreIntf)
                 .front();
-        sdbusplus::message::variant<std::string> property =
-            convertForMessage(value);
+        std::variant<std::string> property = convertForMessage(value);
 
         auto method = chassis::internal::dbus.new_method_call(
             chassis::internal::cache::objects