xfree86: Call ScreenInit for protocol screens before GPU screens
During startup, the xfree86 DDX's InitOutput() calls PreInit for protocol screens first, and then GPU screens. On teardown, dix_main() calls CloseScreen in the reverse order: GPU screens first starting with the last one and then working backwards, and then protocol screens also in reverse order. InitOutput() calls ScreenInit in the wrong order: for GPU screens first and then for protocol screens. This causes a problem for drivers that have global state that is tied to the first screen that calls ScreenInit. Fix this by simply re-ordering the for loops to call PreInit for protocol screens first and then for GPU screens second.