[USB] Fixed some compiler warnings

Author: cmaglie

hardware/arduino/avr/cores/arduino/USBCore.h

@@ -99,8 +99,8 @@
 
 // bEndpointAddress in Endpoint Descriptor
 #define USB_ENDPOINT_DIRECTION_MASK            0x80
-#define USB_ENDPOINT_OUT(addr)                 ((addr) | 0x00)
-#define USB_ENDPOINT_IN(addr)                  ((addr) | 0x80)
+#define USB_ENDPOINT_OUT(addr)                 (lowByte((addr) | 0x00))
+#define USB_ENDPOINT_IN(addr)                  (lowByte((addr) | 0x80))
 
 #define USB_ENDPOINT_TYPE_MASK                 0x03
 #define USB_ENDPOINT_TYPE_CONTROL              0x00
@@ -277,4 +277,4 @@ typedef struct
 #define D_CDCCS4(_subtype,_d0)		{ 4, 0x24, _subtype, _d0 }
 
 
-#endif
+#endif