net: switchdev: remove stray semicolon in switchdev_handle_fdb_del_to_device shim

With the semicolon at the end, the compiler sees the shim function as a
declaration and not as a definition, and warns:

'switchdev_handle_fdb_del_to_device' declared 'static' but never defined

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 8ca07176 ("net: switchdev: introduce a fanout helper for SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>