[commands] Fix exceptions in HelpCommand

discord/ext/commands/help.py

@@ -271,7 +271,7 @@ class HelpCommand(HelpCommandCommand, Generic[ContextT]):
         )
 
     async def __call__(self, context: ContextT, *args: Any, **kwargs: Any) -> Any:
-        return await self.command_callback(context, *args, **kwargs)
+        return await self._set_context(context, *args, **kwargs)
 
     async def _set_context(self, context: ContextT, *args: Any, **kwargs: Any) -> Any:
         _context.set(context)
@@ -288,7 +288,7 @@ class HelpCommand(HelpCommandCommand, Generic[ContextT]):
         bot.add_command(self)  # type: ignore
 
     def _remove_from_bot(self, bot: BotBase) -> None:
-        bot.remove_command(self)  # type: ignore
+        bot.remove_command(self.name)
         self._eject_cog()
 
     async def invoke(self, ctx: ContextT) -> None: