sensors: don't pass excess conn handler

We don't need to pass connection handler to setInitialProperties method
since it already part of the sensor class.

Tested: no changes in behaviour.
Signed-off-by: Andrei Kartashev <a.kartashev@yadro.com>
Change-Id: Icaaccbeaf14e22648a6a1bce381f0f0a606b0ddd
diff --git a/src/TachSensor.cpp b/src/TachSensor.cpp
index 09194f2..d0051a0 100644
--- a/src/TachSensor.cpp
+++ b/src/TachSensor.cpp
@@ -90,7 +90,7 @@
                  "/xyz/openbmc_project/sensors/fan_tach/" + name}});
         itemAssoc->initialize();
     }
-    setInitialProperties(conn, sensor_paths::unitRPMs);
+    setInitialProperties(sensor_paths::unitRPMs);
     setupRead();
 }