io_uring: fix memory leak when cache init fail

Exit the percpu ref when cache init fails to free the data memory with
in struct percpu_ref.

Fixes: 206aefde ("io_uring: reduce/pack size of io_ring_ctx")
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240923100512.64638-1-kanie@linux.alibaba.com


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