media: go7007: fix two sparse warnings

drivers/media/usb/go7007/go7007-v4l2.c:637:2: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
drivers/media/usb/go7007/go7007-fw.c:1507:3: warning: this statement may fall through [-Wimplicit-fallthrough=]

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