staging: fbtft: Fix duplicate arguments to bitwise AND

Fix duplicated arguments to bitwise & operator.
Issue detected by coccinelle.

Signed-off-by: Jamal Shareef <jamal.k.shareef@gmail.com>
Link: https://lore.kernel.org/r/20191023215105.18049-1-jamal.k.shareef@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>