default environment: force a specific return value

Since commit a162dfe503 the ifup command runs
this file as a script. Due to a hush misbehave it could happen it returns
an error code by accident.

For example if the last instructions in this file are:

 if [ false ]; then
    echo "friesel"
 fi

the hush returns 1 after running this script instead of 0 and in this case
the ifup command fails.

I know, the correct fix would be to fix the hush, because it is a generic
issue...but how?

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

defaultenv/defaultenv-2-base/network/eth0

@@ -14,3 +14,5 @@ serverip=
 #ethaddr=xx:xx:xx:xx:xx:xx
 
 # put code to discover eth0 (i.e. 'usb') to /env/network/eth0-discover
+
+exit 0