Core/Vehicles: Correct usage of npc_spellclick_spells instead of blatant hacks for vehicle entry.

Note: This may break a few vehicles, but only due to the absence of proper, non-hackish data.

src/server/game/Globals/ObjectMgr.h

@@ -335,7 +335,7 @@ struct SpellClickInfo
     SpellClickUserTypes userType;
 
     // helpers
-    bool IsFitToRequirements(Player const* player, Creature const * clickNpc) const;
+    bool IsFitToRequirements(Unit const* clicker, Unit const * clickee) const;
 };
 
 typedef std::multimap<uint32, SpellClickInfo> SpellClickInfoMap;