Fix: allow CIPSO labels with zero categories

There was false restriction in smack_cipso_add_from_file() that
disallowed CIPSO labels without categories.

For example, this example given in the SMACK kernel documentation
should be perfectly legal:

TopSecret 7
Change apply_cipso_cb() to use proper apply_cipso_file()

apply_cipso_cb() used improper apply_rules_file(). Changed this to
call apply_cipso_file() instead.
Merge branch 'cipso_bug' of git://github.com/zos/smack into zos-cipso_bug
Cleaning error logs for rules applying utilities

Removed perror logs from main utilities files. Moved error logs
inside /utils/common.c. Errors are logged from I/O operations and
applying rules/cipso from files.