If /proc/self/fd/X did not exist, the actual error is that the file
descriptor was invalid.
go-fuse's pathfs prefers using an open fd even for path-based operations
but does not take any locks to prevent the fd from being closed.
Instead, it retries the operation by path if it get EBADF. So this
change allows the retry logic to work correctly.
This fixes the error
rsync: failed to set times on "/tmp/ping.Kgw.mnt/linux-3.0/[...]/.dvb_demux.c.N7YlEM":
No such file or directory (2)
that was triggered by pingpong-rsync.bash.
5b1eed35ee