regulator: fixed: Fix incorrectly formatted kerneldoc "Return" section

kernel-doc complains about missing "Return" section for kerneldoc of
of_get_fixed_voltage_config(). The kerneldoc has a description
about the return values, just not in the format kernel-doc wants.

Convert it to use the proper "Return:" section header. The existing
description have been reworded and moved around to fit the grammar and
formatting.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20240829085131.1361701-7-wenst@chromium.orgSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/fixed.c

@@ -158,8 +158,10 @@ static int reg_fixed_get_irqs(struct device *dev,
  * @desc: regulator description
  *
  * Populates fixed_voltage_config structure by extracting data from device
- * tree node, returns a pointer to the populated structure of NULL if memory
- * alloc fails.
+ * tree node.
+ *
+ * Return: Pointer to a populated &struct fixed_voltage_config or %NULL if
+ *	   memory allocation fails.
  */
 static struct fixed_voltage_config *
 of_get_fixed_voltage_config(struct device *dev,