Minor code style fixes, documentation improvements.

LUFA/DoxygenPages/ChangeLog.txt

@@ -20,6 +20,7 @@
   *   - Fixed incorrect XMEGA DFLL reference frequency (thanks to Martin Aakerberg)
   *   - Fixed possible infinite loop in the control endpoint stream write function (thanks to Clayton Knight)
   *   - Fixed missing HID report ID prefix on HID class driver GetReport request responses (thanks to Bert van Hall)
+  *   - Fixed incorrect XMEGA USB controller clock division factory for non-Full Speed operation (thanks to Bert van Hall)
   *  - Library Applications:
   *   - Fixed spurious 0xFE USART byte sent in the USBtoSerial project when the baud rate is changed (thanks to Carl Kjeldsen)
   *   - Fixed blocking USART reads causing low throughput on slow baud rates in the USBtoSerial project (thanks to Nevada Smith)

LUFA/Drivers/USB/Core/XMEGA/USBController_XMEGA.c

@@ -110,7 +110,6 @@ void USB_Disable(void)
 void USB_ResetInterface(void)
 {
 	uint8_t PrescalerNeeded;
-	uint8_t nbit = 0;
 
 	#if defined(USB_DEVICE_OPT_FULLSPEED)
 	if (USB_Options & USB_DEVICE_OPT_LOWSPEED)
@@ -121,12 +120,14 @@ void USB_ResetInterface(void)
 	PrescalerNeeded = F_USB / 6000000;
 	#endif
 
-	while (PrescalerNeeded && nbit < 7) {
+	uint8_t DividerIndex = 0;
+	while (PrescalerNeeded > 0)
+	{
+		DividerIndex++;
 		PrescalerNeeded >>= 1;
-		nbit++;
 	}
 
-	CLK.USBCTRL = (nbit - 1) << CLK_USBPSDIV_gp;
+	CLK.USBCTRL = (DividerIndex - 1) << CLK_USBPSDIV_gp;
 
 	if (USB_Options & USB_OPT_PLLCLKSRC)
 	  CLK.USBCTRL |= (CLK_USBSRC_PLL_gc   | CLK_USBSEN_bm);