doc: replace @return by Return:

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/backlight.h b/include/backlight.h
index b44da50..c841882 100644
--- a/include/backlight.h
+++ b/include/backlight.h
@@ -41,7 +41,7 @@
  * backlight_enable() - Enable a backlight
  *
  * @dev:	Backlight device to enable
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, -ve on error
  */
 int backlight_enable(struct udevice *dev);
 
@@ -50,7 +50,7 @@
  *
  * @dev:	Backlight device to update
  * @percent:	Brightness value (0 to 100, or BACKLIGHT_... value)
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, -ve on error
  */
 int backlight_set_brightness(struct udevice *dev, int percent);