agp/intel: Promote warning about failure to setup flush to error.

Make sure we always detect when we fail to correctly allocate the Isoch
Flush Page and print an error to warn the user about the likely memory
corruption that will result in invalid rendering or worse.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

drivers/char/agp/intel-gtt.c

@@ -1068,11 +1068,11 @@ static void intel_i9xx_setup_flush(void)
 		intel_i915_setup_chipset_flush();
 	}
 
-	if (intel_private.ifp_resource.start) {
+	if (intel_private.ifp_resource.start)
 		intel_private.i9xx_flush_page = ioremap_nocache(intel_private.ifp_resource.start, PAGE_SIZE);
 	if (!intel_private.i9xx_flush_page)
-			dev_info(&intel_private.pcidev->dev, "can't ioremap flush page - no chipset flushing");
-	}
+		dev_err(&intel_private.pcidev->dev,
+			"can't ioremap flush page - no chipset flushing\n");
 }
 
 static int intel_i9xx_configure(void)