fix some glitches and add null pointer checks, if wrong code is configured

git-svn-id: svn://svn.dd-wrt.com/DD-WRT@24995 52c4871e-980c-0410-b1e0-e73912ce01f8
more sysprintf replacements

git-svn-id: svn://svn.dd-wrt.com/DD-WRT@24996 52c4871e-980c-0410-b1e0-e73912ce01f8