control: Remove unused constant in fan.cpp

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I584abc403b6c54270efaeb77eff9352a0a1de820
diff --git a/control/fan.cpp b/control/fan.cpp
index d6fca54..581d708 100644
--- a/control/fan.cpp
+++ b/control/fan.cpp
@@ -26,7 +26,6 @@
 namespace control
 {
 
-constexpr auto FAN_SENSOR_PATH = "/xyz/openbmc_project/sensors/fan_tach/";
 constexpr auto FAN_TARGET_PROPERTY = "Target";
 
 Fan::Fan(sdbusplus::bus_t& bus, const FanDefinition& def) :