Hopefully fixes crash happening when restarting races.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/branches/irrlicht@4271 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/graphics/skid_marks.cpp

@@ -62,6 +62,7 @@ void SkidMarks::reset()
     }
     m_left.clear();
     m_right.clear();
+    m_nodes.clear();
     m_skid_marking = false;
     m_current      = -1;
 }   // reset