umount: instead of non-standard -D, use -d with opposite meaning
  (closes bug 1604)
umount: do not try to free loop device or erase mtab if remounted ro
umount: do not complain several times about the same mountpoint

function                                             old     new   delta
umount_main                                          646     638      -8
packed_usage                                       23662   23652     -10
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(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18)             Total: -18 bytes

2 files changed