Merge pull request ARMmbed#7324 from soramame21/ren-f429

Fix LED_RED mapping on NUCLEO_F429ZI

Author: Cruz Monrreal

targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F429xI/TARGET_NUCLEO_F429ZI/PinNames.h

@@ -259,7 +259,7 @@ typedef enum {
     LED2        = PB_7,  // Blue
     LED3        = PB_14, // Red
     LED4        = PB_0,
-    LED_RED     = LED2,
+    LED_RED     = LED3,
     USER_BUTTON = PC_13,
     // Standardized button names
     BUTTON1 = USER_BUTTON,