test: fix wait_for_instantlock calls in test_instantsend_after_restart

The merge of dashpay#7240 and dashpay#7241 left two call sites in
test_instantsend_after_restart using the old positional signature
wait_for_instantlock(txid, node). After dashpay#7241 changed the signature
to *txids with keyword-only nodes=, the node object was silently
consumed as a second txid, causing the wait to always time out.

Use the new consolidated API which handles mempool sync and checks
all nodes by default.

Author: thepastaclaw

test/functional/p2p_instantsend.py

@@ -139,10 +139,7 @@ def test_instantsend_after_restart(self):
         receiver = self.nodes[self.receiver_idx]
         sender_addr = sender.getnewaddress()
         fund_id = self.nodes[0].sendtoaddress(sender_addr, 1)
-        self.bump_mocktime(30)
-        self.sync_mempools()
-        for node in self.nodes:
-            self.wait_for_instantlock(fund_id, node)
+        self.wait_for_instantlock(fund_id)
         tip = self.generate(self.nodes[0], 2)[-1]
         self.bump_mocktime(30)
         self.wait_for_chainlocked_block_all_nodes(tip)
@@ -199,10 +196,7 @@ def check_mn_peers(node=mn_node, my_hash=mn_info.proTxHash):
 
         # send a TX — needs IS lock from all restarted MNs, no new blocks mined
         is_id = sender.sendtoaddress(receiver_addr, 0.5)
-        self.bump_mocktime(30)
-        self.sync_mempools()
-        for node in self.nodes:
-            self.wait_for_instantlock(is_id, node)
+        self.wait_for_instantlock(is_id)
         self.log.info("InstantSend lock succeeded after full restart")
 
         # clean up