For st_dev in struct stat, the value 0 is
an error. Make sure rootfs has value 1.
This fixes the coreutils cp -ax issue (although that
code has already been improved in coreutils, too) and
somewhat fixes the switch_root problem in util-linux.
It is still possible that rootfs gets an FSID >1 in
future versions, so util-linux still needs to be fixed.
This is unrelated to the mount id issue in
/proc/*/mountinfo - the mount id may still be
zero.
* Revert a patch that always enables autosuspend on intel bluetoothh
xhci still sucks and breaks this. I am reverting this
commit for reasons that are in no way selfish.
