Print explicit error message on iSCSI boot failure, and add

"Permission denied" as an error text to strerror().

src/hci/strerror.c

@@ -57,3 +57,4 @@ struct errortab enoem __errortab = { ENOMEM, "Out of memory" };
 struct errortab einval __errortab = { EINVAL, "Invalid argument" };
 struct errortab enospc __errortab = { ENOSPC, "No space left on device" };
 struct errortab eio __errortab = { EIO, "Input/output error" };
+struct errortab eacces __errortab = { EACCES, "Permission denied" };