fix(nav): update remaining call of plot_course()

nav.py

@@ -109,7 +109,7 @@ def asteroid_route(belt: str) -> list[str]:
 
 def print_plan(destination: str) -> None:
     """Print the flight plan for a destination."""
-    route, total, days, fuel = plan(destination)
+    route, total, days, fuel = plot_course(destination)
     print("Route: " + " -> ".join(NAMES[w] for w in route))
     print(f"Distance: {total:.1f} million km")
     print(f"Travel time: {round(days)} days")