staging: wilc1000: rename hWFIDrv in host_int_set_operation_mode

This patch replaces hWFIDrv with wfi_drv that is first argument of
host_int_set_operation_mode to avoid camelcase.

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