staging: wilc1000: fix parameter name of host_int_del_beacon

This patch changes struct host_if_drv of host_int_del_beacon function
declaration from hWFIDrv to hif_drv.
With this change, first parameter name of this function declaration and
definition has same name as hif_drv.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>