Replace some 16-bit calls by their 32-bit equivalents.

diff --git a/windows/mdi.c b/windows/mdi.c
index 07cd19c..cfad061 100644
--- a/windows/mdi.c
+++ b/windows/mdi.c
@@ -2343,7 +2343,7 @@
 			newPos = maxPos;
 			break;
 	case SB_ENDSCROLL:
-			CalcChildScroll16(hWnd,(uMsg == WM_VSCROLL)?SB_VERT:SB_HORZ);
+			CalcChildScroll(hWnd,(uMsg == WM_VSCROLL)?SB_VERT:SB_HORZ);
 			return;
     }