Made mkfs arguments optional and added rootdelay

The problem is that we have been creating file systems with -f flag
while it is suitable only for xfs, but not for any other file systems.
Another problem is that some hardware such as ancient Dell equipment
delays exposing raid volumes and grub usually fails not waiting for root
file system is available. rootdelay=90 allows to avoid that kind of
unexpected behaviour.

Backport to stable/4.1 includes a fix for a format string problem that
was present in the original commit merged to master.

Change-Id: I199077b4bf53fdcdc17a89fb4c8ad82bfd966a87
Co-Authored-By: Dmitry Borodaenko <dborodaenko@mirantis.com>
Merge "Made mkfs arguments optional and added rootdelay" into stable/4.1