vfs: make File lock and Dir lock not overlap to avoid deadlock
vfs: make File lock and Dir lock not overlap to avoid deadlock

This was caused by this commit which wasn't part of 1.51.0

3c91abce745000cd vfs: fix race condition caused by unlocked reading of Dir.path

ncw/rclone,ncw/rclone,ncw/rclone,ncw/rclone