[archiso] Add support to setups with more than one network card.

Otherwise archiso_pxe_nbd hook can configure the incorrect network card,
because ipconfig will configure all interfaces available.

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@yahoo.com.ar>

archiso/hooks/archiso_pxe_nbd

@@ -5,6 +5,15 @@ run_hook () {
     : > /ip_opts
 
     if [ -n "${ip}" ]; then
+        if [ -n "${BOOTIF}" ]; then
+            bootif_mac=${BOOTIF#01-}
+            bootif_mac=${bootif_mac//-/:}
+            bootif_dev=$(grep -l $bootif_mac /sys/class/net/*/address)
+            bootif_dev=${bootif_dev#/sys/class/net/}
+            bootif_dev=${bootif_dev%/address}
+            ip="$ip::$bootif_dev"
+        fi
+
         # setup network and save some values
         ipconfig "ip=${ip}" | while read line; do
             # echo ":: ${line}"