Fix name of some syscalls in docs

[aconz2]

No description provided.

[quininer]

I think you're right, but the docs comes from liburing manpage. https://github.com/axboe/liburing/blob/master/man/io_uring_enter.2#L1155

I would like docs to be simply consistent with manpage, would you like to fix liburing manpage as well?

[aconz2]

Oh the plot thickens, makes sense, yes I will do that. Already confused about futex2 since that is almost a thing with futex_{wait,wake,waitv but there is no futex2(2) man page (nor for those calls) so I will try to figure that out and get back to you

[aconz2]

updated to drop the futex2 changes, liburing now reflects the same changes

[quininer]

Thank you!