core, eth: minor txpool event cleanups

eth/protocol_test.go

@@ -116,7 +116,7 @@ func testRecvTransactions(t *testing.T, protocol int) {
 			t.Errorf("added wrong tx hash: got %v, want %v", added[0].Hash(), tx.Hash())
 		}
 	case <-time.After(2 * time.Second):
-		t.Errorf("no TxsPreEvent received within 2 seconds")
+		t.Errorf("no NewTxsEvent received within 2 seconds")
 	}
 }