net_processing: move CNode data access out of lock

CNode::m_relays_tx and CNode::m_bloom_filter_loaded access don't require
the Peer::TxRelay::m_bloom_filter_mutex lock, so move them out of the
lock scope.

See https://github.com/bitcoin/bitcoin/pull/21160#discussion_r736785417
and https://github.com/bitcoin/bitcoin/pull/21160#discussion_r736785662.

src/net_processing.cpp

@@ -2715,8 +2715,10 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         pfrom.m_limited_node = (!(nServices & NODE_NETWORK) && (nServices & NODE_NETWORK_LIMITED));
 
         if (peer->m_tx_relay != nullptr) {
+            {
                 LOCK(peer->m_tx_relay->m_bloom_filter_mutex);
                 peer->m_tx_relay->m_relay_txs = fRelay; // set to true after we get the first filter* message
+            }
             if (fRelay) pfrom.m_relays_txs = true;
         }
 
@@ -4029,11 +4031,13 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             Misbehaving(pfrom.GetId(), 100, "too-large bloom filter");
         }
         else if (peer->m_tx_relay != nullptr)
+        {
             {
                 LOCK(peer->m_tx_relay->m_bloom_filter_mutex);
                 peer->m_tx_relay->m_bloom_filter.reset(new CBloomFilter(filter));
-            pfrom.m_bloom_filter_loaded = true;
                 peer->m_tx_relay->m_relay_txs = true;
+            }
+            pfrom.m_bloom_filter_loaded = true;
             pfrom.m_relays_txs = true;
         }
         return;
@@ -4076,10 +4080,13 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         if (peer->m_tx_relay == nullptr) {
             return;
         }
+
+        {
             LOCK(peer->m_tx_relay->m_bloom_filter_mutex);
             peer->m_tx_relay->m_bloom_filter = nullptr;
-        pfrom.m_bloom_filter_loaded = false;
             peer->m_tx_relay->m_relay_txs = true;
+        }
+        pfrom.m_bloom_filter_loaded = false;
         pfrom.m_relays_txs = true;
         return;
     }