Force creation of ext2/3/4 and ntfs on whole disk devices (#683643)

Creation of ext2/3/4 and ntfs file systems fails in GParted on whole
disk devices with these errors.

    # mkfs.ext4 -L "" /dev/sdb < /dev/null
    mke2fs 1.42.9 (4-Feb-2014)
    /dev/sdb is entire device, not just one partition!
    Proceed anyway? (y,n)
    # echo $?
    1

    # mkntfs -Q -v -L "" /dev/sdc
    /dev/sdc is entire device, not just one partition.
    Refusing to make a filesystem here!
    # echo $?
    1

Add force flag, -F, to both mkfs commands to make them work.

Bug 683643 - Doesn't properly support partitionless drives.