staging: vt6656: remove unnecessary parenthesis

Remove unnecessary parenthesis to abide by kernel
coding-style.

Signed-off-by: Amir Mahdi Ghorbanian <indigoomega021@gmail.com>
Link: https://lore.kernel.org/r/20191230155520.GA27072@user-ThinkPad-X230
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>