Update kernel version in syscall-names.list to 4.17

[Florian Weimer]

On 06/04/2018 10:41 PM, Joseph Myers wrote:
> As far as I can tell, Linux 4.17 does not add any new syscalls; this
> patch updates the version number in syscall-names.list to reflect that
> it's still current for 4.17.

I double-checked this against the kernel sources.  io_pgetevents is 
coming, but it's not yet in 4.17.  So this is okay.

Thanks,
Florian