Add a forced delay to udev settle in chroot environments

[win32asm]

When running in a chroot environment (e.g.mock) there is a race between udev actually settling the discovered loopback/dm device names and a program running 'udevadm settle', as latter becomes a no-op in chroot:

sh-5.1# udevadm settle Running in chroot, ignoring request.

This patch grabs stdout of 'udevadm settle' command, tries to determine whether the command was ignored, and adds an 1s delay if it was.

1s delay was chosen arbitrary, to succeed in used environment. However, it should be sufficient for most chrooted environments, as significant device changes are not expected there.

[StorageGhoul]

Can one of the admins verify this patch?

[win32asm]

@vojtechtrefny please proceed with the merge.

[vojtechtrefny]

Jenkins, ok to test.