Fix policy for pkcsslotd from opencryptoki

opencryptoki's daemon cannot be run in Rawhide due to several AVCs. These changes fix it for me.

audit2allow output:
> allow pkcs_slotd_t passwd_file_t:file { read getattr open };
> allow pkcs_slotd_t tmpfs_t:file { read write };
> allow pkcs_slotd_t var_lock_t:dir { write add_name };
> allow pkcs_slotd_t var_lock_t:file { read lock create open setattr };
> allow pkcs_slotd_t var_lock_t:lnk_file read;