martin dc1011f1c9 Available block count may be negative - so make the calculation signed. ...

This avoids output like:
Filesystem      1K-blocks     Used     Avail Capacity  Mounted on
/dev/wd1a           11799    11276 9223372036854775741   100%    /boot

2004-07-04 15:31:50 +00:00

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df.1

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df.c

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Makefile

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