Clean up the X11 definitions after the X11 includes.

This fixes build problems after 8f43c5e: sm.h would include
X11/SM/SMlib.h, which includes X11/ICE/ICElib.h, which adds a #define
Status int, which breaks qdeclarativeview.h, included by
moc_declarative.cpp.

Reviewed-by: mgraesslin