Improve some comment documentation following the extensions refactor

Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>

ssl/ssl_sess.c

@@ -432,8 +432,7 @@ int ssl_get_new_session(SSL *s, int session)
  * ssl_get_prev attempts to find an SSL_SESSION to be used to resume this
  * connection. It is only called by servers.
  *
- *   ext: ClientHello extensions (including length prefix)
- *   session_id: ClientHello session ID.
+ *   hello: The parsed ClientHello data
  *
  * Returns:
  *   -1: error

ssl/statem/statem_lib.c

@@ -175,6 +175,10 @@ static int compare_extensions(const void *p1, const void *p2)
  * types, and 0 if the extensions contain duplicates, could not be successfully
  * parsed, or an internal error occurred.
  */
+/*
+ * TODO(TLS1.3): Refactor ServerHello extension parsing to use this and then
+ * remove tls1_check_duplicate_extensions()
+ */
 int tls_collect_extensions(PACKET *packet, RAW_EXTENSION **res,
                              size_t *numfound, int *ad)
 {

ssl/t1_lib.c

@@ -2888,8 +2888,11 @@ int tls_get_ticket_from_client(SSL *s, CLIENTHELLO_MSG *hello,
 }
 
 /*
- * Sets the extended master secret flag is set if the extension is present
- * in the ClientHello
+ * Sets the extended master secret flag if the extension is present in the
+ * ClientHello
+ * Returns:
+ *  1 on success
+ *  0 on error
  */
 int tls_check_client_ems_support(SSL *s, CLIENTHELLO_MSG *hello)
 {