sensorhandler: removed un-needed sd_bus_ref

sdbusplus's bus object has a change in semantics that no longer
require a 'sd_bus_ref' call.  See changes for openbmc/openbmc#1432.

Change-Id: I6e953cfbd83abec1534e75b8fbf6c7e5b711ceb3
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/sensorhandler.cpp b/sensorhandler.cpp
index 95d8ad0..892511a 100644
--- a/sensorhandler.cpp
+++ b/sensorhandler.cpp
@@ -410,7 +410,7 @@
     }
     objects.emplace(iter->second.sensorPath, std::move(interfaces));
 
-    sdbusplus::bus::bus bus{sd_bus_ref(ipmid_get_sd_bus_connection())};
+    sdbusplus::bus::bus bus{ipmid_get_sd_bus_connection()};
     using namespace std::string_literals;
     static const auto intf = "xyz.openbmc_project.Inventory.Manager"s;
     static const auto path = "/xyz/openbmc_project/inventory"s;