(the utmpentry.c code), specifically with respect to who owns them and
when to free them. Now they're owned by utmpentry.c, only. Abolish the
freeutentries() function, which was the wrong abstraction; add instead
endutentries(), which flushes out the internally managed memory.
Update callers as necessary. Some (e.g. talkd) had been leaking memory;
others (e.g. syslogd) had been accidentally freeing and reloading utmp
more often than necessary. There are a couple untidy bits in users and
rwhod that someone should look after sometime, maybe.
Fixes PR bin/35131, which was about talkd's memory leak.
christos