Merge bitcoin/bitcoin#24266: util: Avoid buggy std::filesystem:::create_directories() call

b9c113a util: Avoid buggy std::filesystem:::create_directories() call (Hennadii Stepanov)

Pull request description:

  Compiled with some libstdc++ versions (e.g., on Ubuntu 20.04) [`std::filesystem:::create_directories()`](https://en.cppreference.com/w/cpp/filesystem/create_directory) call [fails](bitcoin/bitcoin#24257 (comment)) to handle symbol links properly.

  No behavior change in comparison to the [pre-20744](bitcoin/bitcoin@c194293) master branch.

  Fixes bitcoin/bitcoin#24257.

ACKs for top commit:
  ryanofsky:
    Code review ACK b9c113a. Nice simplification and fix
  MarcoFalke:
    review ACK b9c113a 🐬

Tree-SHA512: 79d940cfc1f68d9b0548fb2ab005e90850b54ac0fb3bb2940afd632d56288d92687579a3176bac3fd0ea3d2dae71e26444f8f7bdb87862414c12866ae5e857c4

Author: MarcoFalke

src/util/system.cpp

@@ -443,14 +443,18 @@ const fs::path& ArgsManager::GetDataDir(bool net_specific) const
     } else {
         path = GetDefaultDataDir();
     }
-    if (net_specific)
-        path /= fs::PathFromString(BaseParams().DataDir());
 
-    if (fs::create_directories(path)) {
-        // This is the first run, create wallets subdirectory too
+    if (!fs::exists(path)) {
         fs::create_directories(path / "wallets");
     }
 
+    if (net_specific && !BaseParams().DataDir().empty()) {
+        path /= fs::PathFromString(BaseParams().DataDir());
+        if (!fs::exists(path)) {
+            fs::create_directories(path / "wallets");
+        }
+    }
+
     path = StripRedundantLastElementsOfPath(path);
     return path;
 }