media: v4l2-subdev: Fix a 64bit bug

The problem is this line here from subdev_do_ioctl().

        client_cap->capabilities &= ~V4L2_SUBDEV_CLIENT_CAP_STREAMS;

The "client_cap->capabilities" variable is a u64.  The AND operation
is supposed to clear out the V4L2_SUBDEV_CLIENT_CAP_STREAMS flag.  But
because it's a 32 bit variable it accidentally clears out the high 32
bits as well.

Currently we only use the first bit and none of the upper bits so this
doesn't affect runtime behavior.

Fixes: f57fa295 ("media: v4l2-subdev: Add new ioctl for client capabilities")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>