host-bmc: dbus_to_event_handler: Remove unused mctp_fd

```
../host-bmc/dbus_to_event_handler.hpp:89:9: error: private field 'mctp_fd' is not used [-Werror,-Wunused-private-field]
   89 |     int mctp_fd;
      |         ^
```

Change-Id: Ia17471784594bf0abfc7ec5fca4c37aff274ecd0
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/host-bmc/dbus_to_event_handler.cpp b/host-bmc/dbus_to_event_handler.cpp
index b6a4ce1..41826d0 100644
--- a/host-bmc/dbus_to_event_handler.cpp
+++ b/host-bmc/dbus_to_event_handler.cpp
@@ -19,10 +19,10 @@
 const std::vector<uint8_t> pdrTypes{PLDM_STATE_SENSOR_PDR};
 
 DbusToPLDMEvent::DbusToPLDMEvent(
-    int mctp_fd, uint8_t mctp_eid, pldm::InstanceIdDb& instanceIdDb,
+    int /* mctp_fd */, uint8_t mctp_eid, pldm::InstanceIdDb& instanceIdDb,
     pldm::requester::Handler<pldm::requester::Request>* handler) :
-    mctp_fd(mctp_fd),
-    mctp_eid(mctp_eid), instanceIdDb(instanceIdDb), handler(handler)
+    mctp_eid(mctp_eid),
+    instanceIdDb(instanceIdDb), handler(handler)
 {}
 
 void DbusToPLDMEvent::sendEventMsg(uint8_t eventType,