V4L/DVB (13120): gspca - pac7311: remove redundant register page switching

Remove redundant register page switching to page 0 when changing the
color control.

Signed-off-by: Marton Nemeth <nm127@freemail.hu>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>