Use fake hostname when killing ns_server.

Otherwise erlang crashes in case it cannot determine hostname on its
own.

Change-Id: I4acd2f24dbfbb7befbfee7a1f29bf3948628c5f4
Reviewed-on: http://review.couchbase.org/8116
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>

membase-server.sh.in

@@ -117,7 +117,7 @@ _stop() {
     nodename=`cat "$NODEFILE"`
 
     erl \
-        -name executioner \
+        -name executioner@executioner \
         -noshell \
         -hidden \
         -setcookie "$cookie" \