[net_processing] Change PeerLogicValidation to hold a connman reference

Hold a reference to connman rather than a pointer because:

- PeerLogicValidation can't run without a connman
- The pointer never gets reseated

The alternative is to always assert that the pointer is non-null before
dereferencing.

Change the name from connman to m_connman at the same time to conform
with current style guidelines.

Author: jnewbery

src/init.cpp

@@ -1384,7 +1384,7 @@ bool AppInitMain(const util::Ref& context, NodeContext& node)
     node.chainman = &g_chainman;
     ChainstateManager& chainman = *Assert(node.chainman);
 
-    node.peer_logic.reset(new PeerLogicValidation(node.connman.get(), node.banman.get(), *node.scheduler, chainman, *node.mempool));
+    node.peer_logic.reset(new PeerLogicValidation(*node.connman, node.banman.get(), *node.scheduler, chainman, *node.mempool));
     RegisterValidationInterface(node.peer_logic.get());
 
     // sanitize comments per BIP-0014, format user agent and check total size