Remove disable_interface from dhcp-all-interfaces

I don't actually think there is a way that disable_interface
would get called on Fedora... because if config_exists
it takes a different path. Furthermore we really don't
want to mess w/ configured interfaces in dhcp-all-interfaces
because that could be side effecty (and is arguably the
job os os-net-config anyways).

This function already did nothing on Debian so removing
shouldn't hurt anything.

Change-Id: Ic53bbab98aa03d487efd290ae8e076045781b5b1

elements/dhcp-all-interfaces/install.d/dhcp-all-interfaces.sh

@@ -46,22 +46,6 @@ function enable_interface() {
 
 }
 
-function disable_interface() {
-    local interface=$1
-
-    serialize_me
-    if [ "$CONF_TYPE" == "netscripts" ]; then
-        local IFCFG_FILE="/etc/sysconfig/network-scripts/ifcfg-$interface"
-        if [ -f "$IFCFG_FILE" ]; then
-            rm $IFCFG_FILE
-        else
-                echo "No link detected, skipping"
-        fi
-        else
-        echo "No link detected, skipping"
-    fi
-}
-
 function config_exists() {
     local interface=$1
     if [ "$CONF_TYPE" == "netscripts" ]; then
@@ -100,7 +84,7 @@ function inspect_interface() {
         if [ "$HAS_LINK" == "1" ] ; then
             enable_interface "$interface"
         else
-            disable_interface "$interface"
+            echo "No link detected, skipping"
         fi
     fi