Resets the current path.
Returns S_OK if successful, or an error value otherwise.
A path consists of a list of zero or more subpaths. Each subpath is a list of one or more points that are connected by straight or curved lines. Each subpath also contains a flag that indicates whether the subpath is closed. If a subpath is closed, the last point of the subpath is connected to the first point by a straight line. Subpaths that have fewer than two points are ignored when the path is painted.