Instead of passing lazy_itable_init=1 and lazy_journal_init=1 to
mkfs.ext4, pass assume_storage_prezeroed=1 which is
stronger and allows the filesystem to skip inode table zeroing
completely instead of simply doing it lazily.
The support for this flag is checked by trying to format a fake
temporary image with mkfs.ext4 and checking its STDERR.
Closes: #4948
Signed-off-by: Niraj Yadav <niryadav@redhat.com>