src/{queue,register,setup}: Don't use `__sys_io_uring*`

Don't use `__sys_io_uring*` for liburing internal. These functions
are now supposed for user backward compatibility.

For now, we use `____sys_io_uring*` (4 underscores). These are
`static inline` functions that wrap the `errno` variable in a kernel
style return value (directly returns negative error code when errors).

The main purpose of this change is to make it possible to remove the
`errno` variable dependency from liburing C sources, so that later
we will be able to build liburing without libc which doesn't use
`errno` variable at all.

Cc: Bedirhan KURT <windowz414@gnuweeb.org>
Cc: Louvian Lyndal <louvianlyndal@gmail.com>
Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Link: https://lore.kernel.org/r/20211003153428.369258-3-ammar.faizi@students.amikom.ac.id
Signed-off-by: Jens Axboe <axboe@kernel.dk>
3 files changed