fix(rm): safely reopen path for parent fd in recursive dir removal

Reopen the current directory path fresh to obtain the parent file descriptor,
avoiding the use of potentially dropped `current_fd` after recursive removal steps.
This ensures robust handling of file descriptors during safe directory deletion on Linux.

Author: mattsu2020

src/uu/rm/src/platform/linux.rs

@@ -391,7 +391,6 @@ pub fn safe_remove_dir_recursive_impl(
             };
 
             // Release current dir fd to keep FD usage low
-            let restore_fd = current_fd.open_subdir(OsStr::new("..")).ok();
             drop(current_fd);
 
             let (child_error, returned_fd) =
@@ -438,6 +437,9 @@ pub fn safe_remove_dir_recursive_impl(
         }
     }
 
-    let parent_fd = current_fd.open_subdir(OsStr::new("..")).ok();
+    // Reopen current path fresh to obtain parent; avoids using possibly dropped fd
+    let parent_fd = DirFd::open(path)
+        .ok()
+        .and_then(|fd| fd.open_subdir(OsStr::new("..")).ok());
     (error, parent_fd)
 }