tests/bzr-definitions

upgrade: remove unnecessary `is None` check

`upgrade_engine.upgrade()` always return the `backuppath` value and there are
not early returns. Hence I don't see how `backuppath` can be None.

Adding extra unncessary safe checks hides unknown bugs. Hence removing it.

Differential Revision: https://phab.mercurial-scm.org/D9675

# this file holds the definitions that are used in various bzr tests

TERM=dumb; export TERM
echo '[extensions]' >> $HGRCPATH
echo 'convert = ' >> $HGRCPATH

glog()
{
    hg log -G --template '{rev}@{branch} "{desc|firstline}" files+: [{file_adds}], files-: [{file_dels}], files: [{file_mods}]\n' "$@"
}

manifest()
{
    echo "% manifest of $2"
    hg -R $1 manifest -v -r $2
}