After r252890 we are naively attempting to pass through the
inode flags. This is technically incorrect as the ext2
inode flags don't match the UFS/system values used in
FreeBSD and a clean conversion is needed.
Some filtering was left in place so the change didn't cause
significant changes in FreeBSD but some of the garbage passed
is likely to be the cause for warning messages in linux.
Fix the issue by resetting the flags before conversion as was
done previously. This also means we will not pass the EXT4_*
inode flags into FreeBSD's inode.
PR: kern/185448
MFC after: 3 days