src: avoid shadowed string in fs_permission
Refs https://github.com/nodejs/node/pull/44004
Addresses the following shadowing issue in fs_permission
:
../../third_party/electron_node/src/permission/fs_permission.h:34:37: error: declaration shadows a field of 'node::permission::FSPermission::RadixTree::Node' [-Werror,-Wshadow]
34 | Node* CreateChild(std::string prefix) {
| ^
../../third_party/electron_node/src/permission/fs_permission.h:24:19: note: previous declaration is here
24 | std::string prefix;
| ^
1 error generated.
Allows Electron to remove a patch.