V4L/DVB (11566): remove broken macro from dvb stv0900_priv.h

It both has unbalanced parentheses and == is not = and it's not used
anywhere anyway.

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>