Fix potential buffer overflow in smack_set_onlycap_from_file()
Fix potential buffer overflow in smack_set_onlycap_from_file()

While reading Smack onlycap labels from a file, take care of possibility
to read a label that is longer than SMACK_LABEL_LEN.

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