Merge bitcoin#14760: Log env path in BerkeleyEnvironment::Flush

4674610 Log env path in BerkeleyEnvironment::Flush (João Barbosa)

Pull request description:

  With `bitcoind -regtest -wallet=w1 -wallet=w2 -debug`, before:

  ```
  BerkeleyEnvironment::Flush: Flush(true)
  BerkeleyEnvironment::Flush: Flushing wallet.dat (refcount = 0)...
  BerkeleyEnvironment::Flush: wallet.dat checkpoint
  BerkeleyEnvironment::Flush: wallet.dat detach
  BerkeleyEnvironment::Flush: wallet.dat closed
  BerkeleyEnvironment::Flush: Flush(true) took              23ms
  BerkeleyEnvironment::Flush: Flush(true)
  BerkeleyEnvironment::Flush: Flushing wallet.dat (refcount = 0)...
  BerkeleyEnvironment::Flush: wallet.dat checkpoint
  BerkeleyEnvironment::Flush: wallet.dat detach
  BerkeleyEnvironment::Flush: wallet.dat closed
  BerkeleyEnvironment::Flush: Flush(true) took              19ms
  ```

  After:
  ```
  BerkeleyEnvironment::Flush: [/Users/joao/Library/Application Support/Bitcoin/regtest/wallets/w1] Flush(true)
  BerkeleyEnvironment::Flush: Flushing wallet.dat (refcount = 0)...
  BerkeleyEnvironment::Flush: wallet.dat checkpoint
  BerkeleyEnvironment::Flush: wallet.dat detach
  BerkeleyEnvironment::Flush: wallet.dat closed
  BerkeleyEnvironment::Flush: Flush(true) took              23ms
  BerkeleyEnvironment::Flush: [/Users/joao/Library/Application Support/Bitcoin/regtest/wallets/w2] Flush(true)
  BerkeleyEnvironment::Flush: Flushing wallet.dat (refcount = 0)...
  BerkeleyEnvironment::Flush: wallet.dat checkpoint
  BerkeleyEnvironment::Flush: wallet.dat detach
  BerkeleyEnvironment::Flush: wallet.dat closed
  BerkeleyEnvironment::Flush: Flush(true) took              19ms
  ```

Tree-SHA512: f90b413cca5d2527324a264ce371dc8baba69f5b541f7d7f6238a8dd79398cbd3c67c0d7a8a0b69aec6c44d77ba26a079c2241427e3669ed22c7da0e4d60039e

Author: laanwj

src/wallet/db.cpp

@@ -725,7 +725,7 @@ void BerkeleyEnvironment::Flush(bool fShutdown)
 {
     int64_t nStart = GetTimeMillis();
     // Flush log data to the actual data file on all files that are not in use
-    LogPrint(BCLog::DB, "BerkeleyEnvironment::Flush: Flush(%s)%s\n", fShutdown ? "true" : "false", fDbEnvInit ? "" : " database not started");
+    LogPrint(BCLog::DB, "BerkeleyEnvironment::Flush: [%s] Flush(%s)%s\n", strPath, fShutdown ? "true" : "false", fDbEnvInit ? "" : " database not started");
     if (!fDbEnvInit)
         return;
     {