fix: link to earlier exercise

Author: mmcky

lectures/ifp_advanced.md

@@ -908,7 +908,7 @@ The JAX implementation provides several advantages:
 ```{exercise}
 :label: ifpa_ex1
 
-Let's repeat our {ref}`earlier exercise <ifp_ex2>` on the long-run
+Let's repeat our {ref}`earlier exercise <ifp_egm_ex2>` on the long-run
 cross sectional distribution of assets.
 
 In that exercise, we used a relatively simple income fluctuation model.