staging: wilc1000: add an argument for Handle_SetWfiDrvHandler

Similar to functions of same layer, this patch add an argument for
Handle_SetWfiDrvHandler function. As a result, the redundant typecasting is
removed.

Signed-off-by: Johnny Kim <johnny.kim@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>