[media] vivid-radio-rx: Don't go past buffer

drivers/media/platform/vivid/vivid-radio-rx.c:198 vivid_radio_rx_s_hw_freq_seek() error: buffer overflow 'vivid_radio_bands' 3 <= 3

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>