Handle case where ip=dhcp

Signed-off-by: David Thurstenson <thurstylark@gmail.com>

archiso/initcpio/hooks/archiso_pxe_common

@@ -22,8 +22,12 @@ run_hook () {
                     break
                 fi
             done
+	    if [[ "${ip}" == "dhcp" ]]; then
+                ip=":::::${bootif_dev}:dhcp"
+	    else
                 ip="${ip}::${bootif_dev}"
             fi
+        fi
 
         # setup network and save some values
         if ! ipconfig -t 20 "ip=${ip}"; then