scripted-diff: Use generate* from TestFramework

-BEGIN VERIFY SCRIPT-
 sed --regexp-extended -i \
     's/((self\.)?(nodes\[[^]]+\]|[a-z_]*(wallet|node)[0-9a-z_]*))\.(generate(|toaddress|block|todescriptor)(\(|, ))/self.\5\1, /g' \
     $(git grep -l generate ./test | grep -v 'test_framework/' | grep -v 'feature_rbf')
-END VERIFY SCRIPT-

test/functional/mempool_persist.py

@@ -160,7 +160,7 @@ class MempoolPersistTest(BitcoinTestFramework):
         self.start_node(0)
 
         # clear out mempool
-        node0.generate(1)
+        self.generate(node0, 1)
 
         # ensure node0 doesn't have any connections
         # make a transaction that will remain in the unbroadcast set