Switch some more usage of the Stat function and the Stat_t type from the
syscall package to golang.org/x/sys. Those were missing in PR #33399.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
The loopback logic is not technically exclusive to the devicemapper
driver. This reorganizes the code such that the loopback code is usable
outside of the devicemapper package and driver.
Signed-off-by: Vincent Batts <vbatts@redhat.com>