liburing: Export `__NR_io_uring_{setup,enter,register}` to user

These macros are not defined in an old <sys/syscall.h> file. Allow
liburing users to get io_uring syscall numbers by including
<liburing.h>.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Link: https://lore.kernel.org/r/20220904073817.1950991-1-ammar.faizi@intel.com
[axboe: improve grammar a bit and kill double line spaces]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2 files changed