Stop emitting Entry propChanged before ifacesAdded

Even though the deferSignal parameter was set to true in the event log
entry D-Bus interface constructor, propertiesChanged signals would still
be emitted when setting the properties to their initial values.  These
were being emitted even before the interfacesAdded signal that is sent
when emit_object_added() is called.

As the code was calling emit_object_added() as soon as it initialized
the properties, it can be deduced that the intended plan was that no
propertiesChanged signals were expected to be sent in the first place.

Fix this by using the sdbusplus functions that take a boolean to skip
sending signals when properties are set to their initial values.

Tested:  With this change, propertiesChanged signals are not emitted
before the interfacesAdded signal for the
xyz.openbmc_project.Logging.Entry interface when either creating or
restoring event logs.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I3548fe29a88719232e26dd806e196c156bcf0078
diff --git a/log_manager.cpp b/log_manager.cpp
index a8e9685..fad602f 100644
--- a/log_manager.cpp
+++ b/log_manager.cpp
@@ -582,7 +582,7 @@
             // validate the restored error entry id
             if (sanity(static_cast<uint32_t>(idNum), e->id()))
             {
-                e->path(file.path());
+                e->path(file.path(), true);
                 e->emit_object_added();
                 if (e->severity() >= Entry::sevLowerLimit)
                 {