drm/i915: Fix unintended recursion in ironlake_disable_rc6

After disabling, we're meant to teardown the bo used for the contexts,
not recurse into ourselves again and preventing module unload.

Reported-and-tested-by: Ben Widawsky <bwidawsk@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9ca1bb2..e79b25b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6575,7 +6575,7 @@
 		POSTING_READ(RSTDBYCTL);
 	}
 
-	ironlake_disable_rc6(dev);
+	ironlake_teardown_rc6(dev);
 }
 
 static int ironlake_setup_rc6(struct drm_device *dev)