Blender Git Loki

Remove noop code from WM_MOUSEWHEEL processing.

ChildWindowFromPoint retrieves the child of the provided window at a
point. In this case it always returns 0 because HWND_DESKTOP is flag
defined as 0, which is never a valid window handle and is not intended
for use in place of a window handle.

Forwarding of mousewheel events was added in adb08def613d, and later
modified to the current unworking state in e9645806f563. Sending mouse
wheel events to the window under the cursor is a system preference and
therefore should not be overridden by Blender, therefore the noop code
has been removed.