rc.shutdown uses nonexistant umount option

[Rich]

The rc.shutdown script in TC4.1 uses umount with the  -d  option which means   "Free loop device if it has been used"
In TC4.7.7 it still uses that option but it no longer exists in umount. It has been replaced with with  -D  whos listed meaning is
"Don't free loop device even if it has been used"  which appears to mean the opposite, so I guess the old  -d  is now the default behavior.
It still appears to accept  -d  even though it is no longer listed as an option. Just thought I'd mention it in case that got carried over into TC5
and you wish to change it.

[curaga]

Yes, it's still used. I don't think it needs to be changed in the script, as it's accepted by bb umount, but thanks for reporting.

[tinypoodle]

It has been replaced with with  -D  whos listed meaning is
"Don't free loop device even if it has been used"  which appears to mean the opposite, so I guess the old  -d  is now the default behavior.

http://git.busybox.net/busybox/commit/?id=86a03bee1d3d6990c03bf500836b19ec8a1c1f12