staging: iio: Remove parentheses on the right hand side of assignment

Remove parentheses on the right hand side of assignment as they are not
needed. Semantic patch used:

@@
expression a, b, c, d;
@@

(
  a = (c == d)
|
  a =
- (
  b
- )
)
Signed-off-by: Janani Ravichandran <janani.rvchndrn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>