Fix kvm_getprocs(3) error reporting in ps(1).

[trasz]

Summary

Previously it just didn't work at all - kvm_getprocs(3) doesn'tupdate the &nentries when it returns NULL. I'm not sure where the previous logic come from, or what it was supposed to do.

[jhb]

Note that 'ps -p <X>' is supposed to only output the header and not fail it seems, so you need to ensure you aren't breaking that. See rS127513 and rS127149 which added the nentries check and explain why. (svn annotate is your friend, there was only one "noise" change of s/0/NULL/ to skip over to find these two commits for the line you are changing)

[cem]

(Adding metadata.)

[trasz]

Explicitly ignore ESRCH.