utils/chsmack: fix hazardous option parsing
utils/chsmack: fix hazardous option parsing

The variable option_index was only set to a proper value if the
given option is a long option. There was also exit() missing on
error condition if SMACK label was invalid.

This patch removes option_index, parameter name from corresponding
error message and adds exit() call when the error condition
realizes.

[jarkko.sakkinen@linux.intel.com: rewrote patch description]

jobol/smack,smack-team/smack,smack-team/smack,jobol/smack