V4L/DVB (11188): pvrusb2: Sub-device update must happen BEFORE state dirty bits are cleared

The sub-device update mechanism relies on various "dirty" bits in the
driver in order to know what pieces of state need to be propagated out
to the various sub-devices.  But that won't work if the dirty bits are
cleared before the update gets a chance to run.  This change ensures
that the update takes place before the dirty bits are cleared.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>