Adjust mbedtls_ccm_free() documentation
@@ -110,8 +110,8 @@ int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
* \brief This function releases and clears the specified CCM context
* and underlying cipher sub-context.
*
- * \param ctx The CCM context to clear. This must be an initialized
- * context.
+ * \param ctx The CCM context to clear. If this is \c NULL, the function
+ * has no effect. Otherwise, this must be initialized.
*
* \note If ctx is \c NULL, the function has no effect.
*/
