Fix optind range checking. optind may index through argc (to the NULL argv entry) on the last option since optind is required to always point to the next command line argument.
Add two more test cases were the final thing on the command line is an invalid long option.
Fix a check that used an older, obsoleted hard-coded value that was not updated.
This should have no impact other than to the getopt() test cases of the OS test.
Tested on the simulator using a modified NSH configuration.
6a679043e6