batch: Downgrade batch submission from a FatalError.

If we wedge the GPU then we will return -EIO for the current batch and
then attempt to reset the GPU. Meanwhile the X server detects the error,
throws a FatalError and to all intents and purposes appears to crash to
the user - whereas before it often just appeared to momentarily freeze.
Of course, on older hardware the server remains frozen until we can find
a way to reset those GPUs at runtime.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

src/i830_batchbuffer.c

@@ -160,7 +160,9 @@ void intel_batch_flush(ScrnInfoPtr scrn)
 	    dri_bo_exec(intel->batch_bo, intel->batch_used, NULL, 0,
 			0xffffffff);
 	if (ret != 0)
-		FatalError("Failed to submit batchbuffer: %s\n",
+		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+			   "Failed to submit batch buffer, expect rendering corruption "
+			   "or even a frozen display: %s.\n",
 			   strerror(-ret));
 
 	while (!list_is_empty(&intel->batch_pixmaps)) {