Bug#343457: boot_xconf: syntax error in 'let LENGTH=($LENGTH - 1)'

[Petter Reinholdtsen <pere@hungry.com>]

[Petter Reinholdtsen]
> I assume the code should subtract 1 from the value of LENGTH.
> Perhaps a posix shell compliant notation should be used instead?

I suspect this patch will solve it, but it is untested.

Index: debian/debian-edu-config.boot_xconf
===================================================================
--- debian/debian-edu-config.boot_xconf (revisjon 5227)
+++ debian/debian-edu-config.boot_xconf (arbeidskopi)
@@ -40,7 +40,7 @@
     LENGTH=8
     while [ $LENGTH -gt 0 ] ; do
       echo $HEXIP
-      let LENGTH=($LENGTH - 1)
+      LENGTH=(($LENGTH - 1))
       HEXIP=$(echo $HEXIP | cut -c -$LENGTH)
     done
 }