Remove some locking in net.h/net.cpp (#1905)

* Remove unnecessary LOCK in ConnectNode

FindNode already does the necessary lock

* Remove unnecessary semicolon

* Remove critical section and assert for ref counts in CNode

nRefCount is an atomic now and thus doesn't need locking anymore.

src/net.cpp

@@ -351,7 +351,6 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         if (IsLocal(addrConnect))
             return NULL;
 
-        LOCK(cs_vNodes);
         // Look for an existing connection
         CNode* pnode = FindNode((CService)addrConnect);
         if (pnode)
@@ -913,7 +912,7 @@ static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate& a, cons
 
 static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) {
     return a.nKeyedNetGroup < b.nKeyedNetGroup;
-};
+}
 
 static bool CompareNodeBlockTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
 {

src/net.h

@@ -808,8 +808,6 @@ public:
     ~CNode();
 
 private:
-    CCriticalSection cs_nRefCount;
-
     CNode(const CNode&);
     void operator=(const CNode&);
 
@@ -842,7 +840,6 @@ public:
 
     int GetRefCount()
     {
-        LOCK(cs_nRefCount);
         assert(nRefCount >= 0);
         return nRefCount;
     }
@@ -866,16 +863,13 @@ public:
 
     CNode* AddRef()
     {
-        LOCK(cs_nRefCount);
         nRefCount++;
         return this;
     }
 
     void Release()
     {
-        LOCK(cs_nRefCount);
         nRefCount--;
-        assert(nRefCount >= 0);
     }