media: ipu6: Drop error argument from ipu6_isys_stream_start()

media: ipu6: Drop error argument from ipu6_isys_stream_start()

error argument for ipu6_isys_stream_start() is always false, remove the
argument. The IPU6_ISYS_BUFFER_LIST_FL_SET_STATE buffer flag also becomes
redundant as a result, remove it as well.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Bingbu Cao <bingbu.cao@intel.com>
Tested-by: Mehdi Djait <mehdi.djait@linux.intel.com> # Dell XPS 9315
Reviewed-by: Mehdi Djait <mehdi.djait@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>