[CSRDLL]: Avoid a potential null pointer dereference.

git-svn-id: svn://svn.reactos.org/reactos/trunk/reactos@63681 97493ccd-5924-5043-b1f5-66cb403b36ce
[URLMON]
* Add HlinkGoBack stub. Needed by *cough* certain apps.
CORE-8174

git-svn-id: svn://svn.reactos.org/reactos/trunk/reactos@63682 97493ccd-5924-5043-b1f5-66cb403b36ce