ARGC is a 'C-ism', but not known/valid in shell-syntax - insert the correct
var $# (=number of args) here. under normal conditions this had no impact,
but we should at least correct it. the error was observable like this:

root@box:~ [ -e "/etc/functions.sh" ] && . /etc/functions.sh
root@box:~ [ -e "/lib/functions.sh" ] && . /lib/functions.sh
root@box:~ . /lib/upgrade/platform.sh
root@box:~ . /lib/upgrade/common.sh
root@box:~ platform_check_image /tmp/myfirmware.bin
ash: bad number
root@box:~ echo $?
0

Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>

SVN-Revision: 40915

Fix sysupgrade for tag-version 7 and 8.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

SVN-Revision: 35724

SVN-Revision: 15900