staging: iio: adc: Remove useless cast on void pointer

staging: iio: adc: Remove useless cast on void pointer

void pointers do not need to be cast to other pointer types.

The semantic patch used to find this:

@r@
expression x;
void* e;
type T;
identifier f;
@@

(
  *((T *)e)
|
  ((T *)x)[...]
|
  ((T *)x)->f
|
- (T *)
  e
)

Build tested it.

Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>