media/vivid-osd: fix info leak in ioctl

media/vivid-osd: fix info leak in ioctl

Orabug: 23330583

commit eda98796aff0d9bf41094b06811f5def3b4c333c upstream.

The vivid_fb_ioctl() code fails to initialize the 16 _reserved bytes of
struct fb_vblank after the ->hcount member. Add an explicit
memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Salva Peiró <speirofr@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b824d64b153a9683aed6730e9f093a7102c36799)

Signed-off-by: Dan Duval <dan.duval@oracle.com>