Change BmGetFileBufferByMemmapFv to BmGetFileBufferByFvFilePath. The original function gets the file buffer only from memory mapped FV device path and leaves GUIDed FV device path to the code below; The new function gets the file buffer from both formats of FV device paths. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Sunny Wang <sunnywang@hpe.com>