staging: ks7010: fix complete_handler

complete_handler() takes void * types as parameters. void * parameters are then
cast to struct types. Call sites for this function either pass in NULL
or pointers to the struct types cast to void *. This casting is
unnecessary and can be removed.

Struct tx_device_buffer (which contains a pointer member to the
complete_handler() function) has as member 'ks_wlan_priv *priv' this is
unnecessary, we always have a pointer to this struct there is no need
to store it here.

The complete_handler can be more clearly defined by using struct
pointer types instead of void * types. The code is currently
unnecessarily complex, storing and passing extraneous pointer
parameters.

Remove unnecessary parameters, unnecessary casting to/from 'void
*'. Fix all call sites involving complete_handler().

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>