The dc_tankvolume_t type had information about metric vs imperial
volume, but we actually want other things too, like the actual usage of
the cylinder.
So rename it to 'dc_tankinfo_t' and extend the semantics from an
enumeration of volume units, to be a bitmap of information flags.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
086b0a799e