usb: get rid of some ReST doc build errors

We need an space before a numbered list to avoid those warnings:

./drivers/usb/core/message.c:478: ERROR: Unexpected indentation.
./drivers/usb/core/message.c:479: WARNING: Block quote ends without a blank line; unexpected unindent.
./include/linux/usb/composite.h:455: ERROR: Unexpected indentation.
./include/linux/usb/composite.h:456: WARNING: Block quote ends without a blank line; unexpected unindent.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

drivers/usb/core/message.c

@@ -474,6 +474,7 @@ EXPORT_SYMBOL_GPL(usb_sg_init);
  * significantly improve USB throughput.
  *
  * There are three kinds of completion for this function.
+ *
  * (1) success, where io->status is zero.  The number of io->bytes
  *     transferred is as requested.
  * (2) error, where io->status is a negative errno value.  The number

include/linux/usb/composite.h

@@ -451,6 +451,7 @@ static inline struct usb_composite_driver *to_cdriver(
  * sure doing that won't hurt too much.
  *
  * One notion for how to handle Wireless USB devices involves:
+ *
  * (a) a second gadget here, discovery mechanism TBD, but likely
  *     needing separate "register/unregister WUSB gadget" calls;
  * (b) updates to usb_gadget to include flags "is it wireless",