maint: fix typos in test comments and old ChangeLog files

maint: fix typos in test comments and old ChangeLog files

Culprits identified and fixed automatically using these commands:
git ls-files|misspellings -f -|perl -nl \
  -e '/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/ or next;' \
  -e '($file,$n,$l,$r)=($1,$2,$3,$4); $q="'\''"; $r=~s/$q/$q\\$q$q/g;'\
  -e 'print "sed -i $q${n}s!$l!$r!$q $file"' | bash
using http://github.com/lyda/misspell-check
* old/fileutils/ChangeLog: Fix typos.
* old/textutils/ChangeLog: Likewise.
* tests/misc/truncate-fail-diag: Likewise.