toolchain/build+install.sh: fixed ancient bug wherein the path for newlib headers passed to gcc's configure was off by one directory level. The bug was reported by Das Signal.

#!/bin/sh

if [ $# != 1 ]
then
	echo "usage: $0 ttyport" 1>&2
	exit 1
fi

fcdir=/opt/freecalypso
exec $fcdir/bin/fc-iram -h pirelli "$1" $fcdir/target-bin/pirexplore.srec