tests/histedit-helpers.sh

cleanup: update references to /help/ that should now be /helptext/

I noticed this only because the WiX build was broken after
2e017696181f. I haven't tested this change with WiX, but it seems
pretty obvious by inspection this should fix it.

Differential Revision: https://phab.mercurial-scm.org/D7472

fixbundle() {
    grep -v 'saving bundle' | grep -v 'saved backup' | \
        grep -v added | grep -v adding | \
        grep -v "unable to find 'e' for patching" | \
        grep -v "e: No such file or directory" | \
    cat
}