ensure deleted object is entry

Some code is coming that puts a new D-Bus object on the
/xyz/openbmc_project/logging/ path. The addCallback() interface
correctly verified the path was an entry but the delCallBack() path did
not.

Tested:
Verified with this change that phosphor-dump-manager no longer core
dumps when one of these new objects is deleted.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Ie702e52b97bc484a44543719e10eab573f8ecb73
diff --git a/elog_watch.cpp b/elog_watch.cpp
index 0a7789c..5dabdb9 100644
--- a/elog_watch.cpp
+++ b/elog_watch.cpp
@@ -168,6 +168,13 @@
         return;
     }
 
+    std::size_t found = objectPath.str.find("entry");
+    if (found == std::string::npos)
+    {
+        // Not a error entry so skip
+        return;
+    }
+
     // Get elog id
     auto eId = getEid(objectPath);