media: v4l2-compat-ioctl32.c: copy m.userptr in put_v4l2_plane32

The struct v4l2_plane32 should set m.userptr as well. The same
happens in v4l2_buffer32 and v4l2-compliance tests for this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: <stable@vger.kernel.org>      # for v4.15 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>