comctl32: Constify some variables (1 of 4)

[Andrew Talbot]

Changelog:
    comctl32: Constify some variables.

diff -urN a/dlls/comctl32/draglist.c b/dlls/comctl32/draglist.c
--- a/dlls/comctl32/draglist.c	2006-10-20 18:07:57.000000000 +0100
+++ b/dlls/comctl32/draglist.c	2007-03-24 10:29:36.000000000 +0000
@@ -91,7 +91,7 @@
 }
 
 /* cleans up after dragging */
-static void DragList_EndDrag(HWND hwnd, DRAGLISTDATA * data)
+static void DragList_EndDrag(HWND hwnd, DRAGLISTDATA const *data)
 {
     KillTimer(hwnd, DRAGLIST_TIMERID);
     ReleaseCapture();