partition_filesystem, vfs_real: Use std::move in ReplaceFileWithSubdirectory() where applicable

Avoids unnecessary atomic increment and decrement operations.

src/core/file_sys/partition_filesystem.cpp

@@ -109,7 +109,7 @@ bool PartitionFilesystem::ReplaceFileWithSubdirectory(VirtualFile file, VirtualD
     pfs_files[offset] = pfs_files.back();
     pfs_files.pop_back();
 
-    pfs_dirs.emplace_back(dir);
+    pfs_dirs.emplace_back(std::move(dir));
 
     return true;
 }