staging: ks7010: remove void * cast

Functions accept a parameter of type 'void *', this is then cast to a
struct ks_wlan_private pointer. All call sites have a struct
ks_wlan_private pointer and cast it to 'void *'. We can remove the
unnecessary casting by changing the parameter type to match the
usage. Functions changed all have internal linkage.

Replace parameter of type 'void *' with 'struct ks_wlan_private
*'. Remove unnecessary casting to and from 'void *'.

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