Retry link check up to 10 times.

Updates the dhcp-all-interfaces element so that the link
check tries up to 10 times.

On some of my machines 3 times (seconds) doesn't appear to
be quite long enough...

Change-Id: Ibf7015162fc890d4de8a417b868b0301146944c0

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

@@ -58,7 +58,7 @@ for interface in $(ls /sys/class/net | grep -v ^lo$) ; do
     ip link set dev $interface up >/dev/null 2>&1
     HAS_LINK="$(get_if_link $interface)"
 
-    TRIES=3
+    TRIES=10
     while [ "$HAS_LINK" == "0" -a $TRIES -gt 0 ]; do
       HAS_LINK="$(get_if_link $interface)"
       if [ "$HAS_LINK" == "1" ]; then