io_uring: hide rsrc tag copy into generic helpers

Make io_rsrc_data_alloc() taking care of rsrc tags loading on
registration, so we don't need to repeat it for each new rsrc type.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5609680697bd09735de10561b75edb95283459da.1623634181.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>