media: ov6650: Fix device node exposed without proper locking

commit 5c49ac3a upstream.

Commit c62b9605 ("media: ov6650: Register with asynchronous
subdevice framework") carelessly requested creation of a video device
node by setting a V4L2_SUBDEV_FL_HAS_DEVNODE flag.  The driver is not
ready for that as it doesn't implement proper locking required for
serialization of IOCTLs.

Fix it by dropping the flag assignment.

Fixes: c62b9605 ("media: ov6650: Register with asynchronous subdevice framework")
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>