Make it clear which functions that are intended to be translation unit local

Do not share functions that are meant to be translation unit local with
other translation units. Use internal linkage for those consistently.

src/init.cpp

@@ -319,12 +319,12 @@ static void registerSignalHandler(int signal, void(*handler)(int))
 }
 #endif
 
-void OnRPCStarted()
+static void OnRPCStarted()
 {
     uiInterface.NotifyBlockTip.connect(&RPCNotifyBlockChange);
 }
 
-void OnRPCStopped()
+static void OnRPCStopped()
 {
     uiInterface.NotifyBlockTip.disconnect(&RPCNotifyBlockChange);
     RPCNotifyBlockChange(false, nullptr);
@@ -595,7 +595,7 @@ struct CImportingNow
 // rev files since they'll be rewritten by the reindex anyway.  This ensures that vinfoBlockFile
 // is in sync with what's actually on disk by the time we start downloading, so that pruning
 // works correctly.
-void CleanupBlockRevFiles()
+static void CleanupBlockRevFiles()
 {
     std::map<std::string, fs::path> mapBlockFiles;
 
@@ -630,7 +630,7 @@ void CleanupBlockRevFiles()
     }
 }
 
-void ThreadImport(std::vector<fs::path> vImportFiles)
+static void ThreadImport(std::vector<fs::path> vImportFiles)
 {
     const CChainParams& chainparams = Params();
     RenameThread("bitcoin-loadblk");
@@ -709,7 +709,7 @@ void ThreadImport(std::vector<fs::path> vImportFiles)
  *  Ensure that Bitcoin is running in a usable environment with all
  *  necessary library support.
  */
-bool InitSanityCheck(void)
+static bool InitSanityCheck(void)
 {
     if(!ECC_InitSanityCheck()) {
         InitError("Elliptic curve cryptography sanity check failure. Aborting.");
@@ -727,7 +727,7 @@ bool InitSanityCheck(void)
     return true;
 }
 
-bool AppInitServers()
+static bool AppInitServers()
 {
     RPCServer::OnStarted(&OnRPCStarted);
     RPCServer::OnStopped(&OnRPCStopped);