banman: add thread annotations and mark members const where possible

Also remove misleading comment. ClearBanned is used by rpc as well.

Author: theuni

src/banman.h

@@ -41,7 +41,7 @@ class BanMan
     BanMan(fs::path ban_file, CClientUIInterface* client_interface, int64_t default_ban_time);
     void Ban(const CNetAddr& netAddr, const BanReason& banReason, int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
     void Ban(const CSubNet& subNet, const BanReason& banReason, int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
-    void ClearBanned(); // needed for unit testing
+    void ClearBanned();
     bool IsBanned(CNetAddr netAddr);
     bool IsBanned(CSubNet subNet);
     bool Unban(const CNetAddr& netAddr);
@@ -57,12 +57,12 @@ class BanMan
     //!clean unused entries (if bantime has expired)
     void SweepBanned();
 
-    banmap_t m_banned;
     CCriticalSection m_cs_banned;
-    bool m_is_dirty;
+    banmap_t m_banned GUARDED_BY(m_cs_banned);
+    bool m_is_dirty GUARDED_BY(m_cs_banned);
     CClientUIInterface* m_client_interface = nullptr;
     CBanDB m_ban_db;
-    int64_t m_default_ban_time;
+    const int64_t m_default_ban_time;
 };
 
 extern std::unique_ptr<BanMan> g_banman;