Fix settingsd core dump/persistence fail
Fix settingsd core dump/persistence fail

The problem was seen only with network settings objects, because they
had paths as following:

A setting d-bus object /foo/bar/baz is persisted in the filesystem with
the same path. This eases re-construction of settings objects when we
restore from the filesystem. This can be a problem though when you have
two objects such as - /foo/bar and /foo/bar/baz. This is because 'bar'
will be treated a file in the first case, and a subdir in the second.
This was causing an exception to be thrown by Cereal, because it found a
dir where it was expecting a file. This also caused us to not persist
certain network setting objects because we couldn't create subdirs
as there were files of the same name.

To solve this, suffix files with a trailing __. The __ is a safe
character sequence to use, because we won't have d-bus object paths
ending with this. With this the objects would be persisted as -
/foo/bar__ and /foo/bar/baz__.

Change-Id: I76b6a0423db1f2f51bd1b6ab2ea5f9cafd1a36d9
Signed-off-by: Deepak Kodihalli <54105a30055f1e07853b8ee7a2f0d75d22ed98c1@in.ibm.com>

openbmc/phosphor-settingsd,openbmc/phosphor-settingsd,openbmc/phosphor-settingsd