oxnas: drop some unused sysupgrade code

First of all platform_do_upgrade_phase2 doesn't seem to be defined
anywhere. Other than that platform_do_upgrade is not likely to be ever
called. There is a call to nand_do_platform_check which triggers
nand_upgrade_stage1 call with "exit 0" in it.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Daniel Golle <daniel@makrotopia.org>

SVN-Revision: 47038

target/linux/oxnas/base-files/lib/upgrade/platform.sh

@@ -15,15 +15,6 @@ platform_check_image() {
 	return $?
 }
 
-platform_do_upgrade() {
-	if [ $$ -ne 1 ]; then
-		echo "not PID 1, upgrade aborted."
-		return 1;
-	fi
-	platform_do_upgrade_phase2 "$1" "$CONF_TAR" "$SAVE_CONFIG"
-}
-
-
 disable_watchdog() {
 	killall watchdog
 	( ps | grep -v 'grep' | grep '/dev/watchdog' ) && {