[media] saa7146: fix compile warning
[media] saa7146: fix compile warning

Fall-out from the recent struct v4l2_framebuffer change.

drivers/media/common/saa7146/saa7146_fops.c: In function ‘saa7146_vv_init’:
drivers/media/common/saa7146/saa7146_fops.c:536:6: warning: assignment from incompatible pointer type [enabled by default]
  fmt = &vv->ov_fb.fmt;
        ^

Signed-off-by: Hans Verkuil <3a513708f73c27e7d36ebc496aa41dad6a3153ea@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <0cae1d1e981e84d16b82ca3d17be8a7f826608d3@samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs