staging: wilc1000: wilc_frame_register: removes unused hif_drv

This patch removes unused hif_drv of wilc_frame_register function.
It's perform an unnecessary null check and debug print log.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>