libpldmresponder: bios_config: Remove unused 'fd' member

```
../libpldmresponder/bios_config.hpp:164:9: error: private field 'fd' is not used [-Werror,-Wunused-private-field]
  164 |     int fd;
      |         ^
```

Change-Id: If4aeb134726fe7bfb2c884c4c4854337a93318bb
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/libpldmresponder/bios_config.cpp b/libpldmresponder/bios_config.cpp
index 51fad71..7112ed2 100644
--- a/libpldmresponder/bios_config.cpp
+++ b/libpldmresponder/bios_config.cpp
@@ -41,12 +41,12 @@
 
 BIOSConfig::BIOSConfig(
     const char* jsonDir, const char* tableDir, DBusHandler* const dbusHandler,
-    int fd, uint8_t eid, pldm::InstanceIdDb* instanceIdDb,
+    int /* fd */, uint8_t eid, pldm::InstanceIdDb* instanceIdDb,
     pldm::requester::Handler<pldm::requester::Request>* handler,
     pldm::responder::platform_config::Handler* platformConfigHandler,
     pldm::responder::bios::Callback requestPLDMServiceName) :
     jsonDir(jsonDir),
-    tableDir(tableDir), dbusHandler(dbusHandler), fd(fd), eid(eid),
+    tableDir(tableDir), dbusHandler(dbusHandler), eid(eid),
     instanceIdDb(instanceIdDb), handler(handler),
     platformConfigHandler(platformConfigHandler),
     requestPLDMServiceName(requestPLDMServiceName)
diff --git a/libpldmresponder/bios_config.hpp b/libpldmresponder/bios_config.hpp
index 7818ac4..5812e3b 100644
--- a/libpldmresponder/bios_config.hpp
+++ b/libpldmresponder/bios_config.hpp
@@ -160,9 +160,6 @@
     pldm::utils::DBusHandler* const dbusHandler;
     BaseBIOSTable baseBIOSTableMaps;
 
-    /** @brief socket descriptor to communicate to host */
-    int fd;
-
     /** @brief MCTP EID of host firmware */
     uint8_t eid;