V4L/DVB (11895): bt8xx: remove always false if

Remove always false if over unsigned int variable

Signed-off-by: Filipe Rosset <rosset.filipe@gmail.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>