thunderbolt: Update retimer.c function documentation

Make retimer.c function documentation compliant with current kernel-doc
standards. No functional changes.

Signed-off-by: Alan Borzeszkowski <alan.borzeszkowski@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Author: aborzesz

drivers/thunderbolt/retimer.c

@@ -27,8 +27,9 @@
  * @buf: Data read from NVM is stored here
  * @size: Number of bytes to read
  *
- * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
- * read was successful and negative errno in case of failure.
+ * Reads retimer NVM and copies the contents to @buf.
+ *
+ * Return: %0 if the read was successful, negative errno in case of failure.
  */
 int tb_retimer_nvm_read(struct tb_retimer *rt, unsigned int address, void *buf,
 			size_t size)
@@ -503,6 +504,8 @@ static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
  * Then Tries to enumerate on-board retimers connected to @port. Found
  * retimers are registered as children of @port if @add is set.  Does
  * not scan for cable retimers for now.
+ *
+ * Return: %0 on success, negative errno otherwise.
  */
 int tb_retimer_scan(struct tb_port *port, bool add)
 {