typo: s/usages/usage

Co-authored-by: Sam Clark <3758302+goatgoose@users.noreply.github.com>

api/unstable/ktls.h

@@ -135,7 +135,7 @@ S2N_API int s2n_connection_ktls_enable_recv(struct s2n_connection *conn);
  * kernel. Likely this requirement can only be met if the application sends
  * less than 35GB AND makes fewer than 24 million calls to s2n_send. If this requirement
  * is violated, s2n-tls will return an S2N_ERR_KTLS_KEY_LIMIT S2N_ERR_T_USAGE error.
- * - Note: s2n-tls uses the `count` argument when checking key usages limits for
+ * - Note: s2n-tls uses the `count` argument when checking key usage limits for
  *   s2n_sendfile, even if the file is smaller than `count` so less than `count`
  *   bytes will be sent. Applications must set reasonable `count` values to ensure
  *   that s2n_sendfile can't violate the key usage limit.