log_manager: remove redundant createWithFFDC

Fold the functionality of creating an event entry with FFDC appended
into a common implementation to avoid code duplication and to ease
further extension and maintainability.

Build-tested with 'openpower-pel-extension' enabled.

Change-Id: I0f8151b782bf42cc7bc0981e58f6ab1e3cda080c
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
diff --git a/extensions/openpower-pels/manager.cpp b/extensions/openpower-pels/manager.cpp
index 9a64722..0689a8b 100644
--- a/extensions/openpower-pels/manager.cpp
+++ b/extensions/openpower-pels/manager.cpp
@@ -636,7 +636,7 @@
         uint8_t, uint8_t, sdbusplus::message::unix_fd>>
         fFDC)
 {
-    _logManager.createWithFFDC(message, severity, additionalData, fFDC);
+    _logManager.create(message, severity, additionalData, fFDC);
 
     return {_logManager.lastEntryID(), _repo.lastPelID()};
 }