Fix variable name of PATH_SEPARATOR in configure.ac
Fix variable name of PATH_SEPARATOR in configure.ac

Otherwise configure doesn't find /sbin/ifdown (by default) on debian.

seanbruno/fbsd-netcf,hallyn/netcf,seanbruno/fbsd-netcf,osier/netcf,emaste/netcf,emaste/netcf,emaste/netcf,hallyn/netcf,osier/netcf,hallyn/netcf,osier/netcf,seanbruno/fbsd-netcf