rxe driver's add_gid() and del_gid() callbacks are doing simple
checks which are already done by the ib core before invoking these
callback routines.
Therefore, code is simplified to skip implementing add_gid() and
del_gid() callback functions.
They are only invoked by ib_core if they are implemented.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>