Don't fail on empty SEL list

If SEL list is empty, "GetSubTreePaths" method call to the
"xyz.openbmc_project.ObjectMapper" interface produces exception
"xyz.openbmc_project.Common.Error.ResourceNotFound".
As it is fine for the SEL log to be empty, this exception needs
special handling in the code.

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: If7ecfee7c404aff079dadaaec27401c9c17daa6f
1 file changed