Fix race on BasePeerLeecher.done

[thaarok]

BasePeerLeecher currently allows race conditions on done boolean field. It reads it in the loop() method without locking any mutex.

A trivial fix would be to add quitMu locking around done reading, however that would lock on every leecher tick, which can lead to performance drop down. From that reason, I have replaced the quitMu mutex with atomic integer instead.

Race condition details:

==================
WARNING: DATA RACE
Write at 0x00c0fabfc720 by goroutine 2181:
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher/basepeerleecher.(*BasePeerLeecher).Terminate()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/basepeerleecher/session.go:85 +0xc8
  github.com/Fantom-foundation/go-opera/gossip/protocols/dag/dagstream/dagstreamleecher.(*Leecher).terminateSession()
      /home/jand/go-opera-norma/gossip/protocols/dag/dagstream/dagstreamleecher/leecher.go:87 +0x64
  github.com/Fantom-foundation/go-opera/gossip/protocols/dag/dagstream/dagstreamleecher.(*Leecher).NotifyChunkReceived()
      /home/jand/go-opera-norma/gossip/protocols/dag/dagstream/dagstreamleecher/leecher.go:223 +0x404
  github.com/Fantom-foundation/go-opera/gossip.(*handler).handleMsg()
      /home/jand/go-opera-norma/gossip/handler.go:1180 +0x54fe
  github.com/Fantom-foundation/go-opera/gossip.(*handler).handle()
      /home/jand/go-opera-norma/gossip/handler.go:852 +0x1bec
  github.com/Fantom-foundation/go-opera/gossip.MakeProtocols.func1()
      /home/jand/go-opera-norma/gossip/service.go:373 +0x1ea
  github.com/ethereum/go-ethereum/p2p.(*Peer).startProtocols.func1()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/p2p/peer.go:407 +0xf4

Previous read at 0x00c0fabfc720 by goroutine 5834:
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher/basepeerleecher.(*BasePeerLeecher).loop()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/basepeerleecher/session.go:118 +0x204
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher/basepeerleecher.(*BasePeerLeecher).Start.func1()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/basepeerleecher/session.go:69 +0x79

Goroutine 2181 (running) created at:
  github.com/ethereum/go-ethereum/p2p.(*Peer).startProtocols()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/p2p/peer.go:405 +0x111
  github.com/ethereum/go-ethereum/p2p.(*Peer).run()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/p2p/peer.go:250 +0x219
  github.com/ethereum/go-ethereum/p2p.(*Server).runPeer()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/p2p/server.go:1081 +0x373
  github.com/ethereum/go-ethereum/p2p.(*Server).launchPeer.func1()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/p2p/server.go:1064 +0x44

Goroutine 5834 (running) created at:
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher/basepeerleecher.(*BasePeerLeecher).Start()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/basepeerleecher/session.go:67 +0xbc
  github.com/Fantom-foundation/go-opera/gossip/protocols/dag/dagstream/dagstreamleecher.(*Leecher).startSession()
      /home/jand/go-opera-norma/gossip/protocols/dag/dagstream/dagstreamleecher/leecher.go:183 +0xc46
  github.com/Fantom-foundation/go-opera/gossip/protocols/dag/dagstream/dagstreamleecher.(*Leecher).startSession-fm()
      <autogenerated>:1 +0x51
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher.(*BaseLeecher).Routine()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/base_leecher.go:64 +0x124
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher.(*BaseLeecher).loop()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/base_leecher.go:78 +0xf1
  github.com/Fantom-foundation/lachesis-base/gossip/basestream/basestreamleecher.(*BaseLeecher).Start.func1()
      /home/jand/go/pkg/mod/github.com/!fantom-foundation/[email protected]/gossip/basestream/basestreamleecher/base_leecher.go:50 +0x68
==================

[jmpike]

Looks good, as long as the package doesn't touch .done and/or .quit directly and uses only the Terminate() and Stopped() interface.

Thank you, Honza.