Staging: i4l: Remove unused variable

Remove unused variable.

This change is made by below coccinelle script:
@@
type T;
identifier i;
constant C;
@@
(
extern T i;
|
- T i;
  <+... when != i
- i = C;
  ...+>
)

Signed-off-by: Sandhya Bankar <bankarsandhya512@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>