Merge bitcoin/bitcoin#22797: test, doc: refer to the correct variable names in p2p_invalid_tx.py

0d9fdd3 test, doc: refer to the correct variable names in p2p_invalid_tx.py (aitorjs)

Pull request description:

  _tx_orphan_no_fee_ and _tx_orphan_invalid_ don't exist as transactions.

  Have been replaced by _tx_orphan_2_no_fee_ and _tx_orphan_2_invalid_ respectively.

  **Motivation**: Comments are more accurate and easy understandable under the tests context (I think).

ACKs for top commit:
  kristapsk:
    utACK 0d9fdd3
  theStack:
    ACK 0d9fdd3 📃

Tree-SHA512: a4cafd931e51fe2a67085e10e9c61178c864c14982664d112b76327e040af08cd1de04eca4a8ae980fad57ba7078017ce02fc60e7658f38380e8172c2ae28b77

Author: fanquake

test/functional/p2p_invalid_tx.py

@@ -141,9 +141,9 @@ def run_test(self):
                 tx_orphan_2_valid,  # The valid transaction (with sufficient fee)
             ]
         }
-        # Transactions that do not end up in the mempool
-        # tx_orphan_no_fee, because it has too low fee (p2ps[0] is not disconnected for relaying that tx)
-        # tx_orphan_invalid, because it has negative fee (p2ps[1] is disconnected for relaying that tx)
+        # Transactions that do not end up in the mempool:
+        # tx_orphan_2_no_fee, because it has too low fee (p2ps[0] is not disconnected for relaying that tx)
+        # tx_orphan_2_invalid, because it has negative fee (p2ps[1] is disconnected for relaying that tx)
 
         self.wait_until(lambda: 1 == len(node.getpeerinfo()), timeout=12)  # p2ps[1] is no longer connected
         assert_equal(expected_mempool, set(node.getrawmempool()))