wintab32: Remove unneeded cast

[Andrew Talbot]

Changelog:
    wintab32: Remove unneeded cast.

diff --git a/dlls/wintab32/wintab32.c b/dlls/wintab32/wintab32.c
index 5f8608b..1ef19d9 100644
--- a/dlls/wintab32/wintab32.c
+++ b/dlls/wintab32/wintab32.c
@@ -143,8 +143,7 @@ static LRESULT WINAPI TABLET_WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam,
                 {
                     prox = MAKELPARAM( wParam, 1 );
                     TABLET_PostTabletMessage(handler, WT_PROXIMITY,
-                                        (WPARAM)handler->handle, (LPARAM)prox,
-                                        TRUE);
+                                        (WPARAM)handler->handle, prox, TRUE);
                 }
                 break;
             }