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/drivers/serial/serial_bcm283x_pl011.c b/drivers/serial/serial_bcm283x_pl011.c
index 2d2e970..fe74629 100644
--- a/drivers/serial/serial_bcm283x_pl011.c
+++ b/drivers/serial/serial_bcm283x_pl011.c
@@ -17,7 +17,7 @@
  * The serial device will only work properly if it has been muxed to the serial
  * pins by firmware. Check whether that happened here.
  *
- * @return true if serial device is muxed, false if not
+ * Return: true if serial device is muxed, false if not
  */
 static bool bcm283x_is_serial_muxed(void)
 {