memory : handle saving/loading null layers in recurrent memory (#14675)
* Update llama-memory-recurrent.cpp
handle saving/loading null layers in recurrent memory
* fixed styling issues and updated comments
* fix styling issue
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
---------
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>