SmNodePointer is no longer used, so drop it.

Change-Id: I5194cc7e1d9e551f4131cbcac0d84351bb2f2eab
Reviewed-on: https://gerrit.libreoffice.org/26146Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Takeshi Abe <tabe@fixedpoint.jp>