compositor: Fix comment of subsurface_commit_to_cache function

commit 57388e44e5 accidentally changed the comment in
compositor.c::subsurface_commit_to_cache

Signed-off-by: Chris Michael <cp.michael@samsung.com>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>
diff --git a/src/compositor.c b/src/compositor.c
index 65abb72..d723b64 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -3033,7 +3033,7 @@
 	 * If this commit would cause the surface to move by the
 	 * attach(dx, dy) parameters, the old damage region must be
 	 * translated to correspond to the new surface coordinate system
-	 * original_mode.
+	 * origin.
 	 */
 	pixman_region32_translate(&sub->cached.damage,
 				  -surface->pending.sx, -surface->pending.sy);