usb: fix some scripts/kernel-doc warnings

When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:

Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'

Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 6efdab0..acb1b0a 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -708,7 +708,10 @@
  * usb_interface_claimed - returns true iff an interface is claimed
  * @iface: the interface being checked
  *
- * Returns true (nonzero) iff the interface is claimed, else false (zero).
+ * Return: %true (nonzero) iff the interface is claimed, else %false
+ * (zero).
+ *
+ * Note:
  * Callers must own the driver model's usb bus readlock.  So driver
  * probe() entries don't need extra locking, but other call contexts
  * may need to explicitly claim that lock.
@@ -745,8 +748,9 @@
  * @buf: where to put the string
  * @size: how big is "buf"?
  *
- * Returns length of the string (> 0) or negative if size was too small.
+ * Return: Length of the string (> 0) or negative if size was too small.
  *
+ * Note:
  * This identifier is intended to be "stable", reflecting physical paths in
  * hardware such as physical bus addresses for host controllers or ports on
  * USB hubs.  That makes it stay the same until systems are physically
@@ -1578,7 +1582,7 @@
  * usb_urb_dir_in - check if an URB describes an IN transfer
  * @urb: URB to be checked
  *
- * Returns 1 if @urb describes an IN transfer (device-to-host),
+ * Return: 1 if @urb describes an IN transfer (device-to-host),
  * otherwise 0.
  */
 static inline int usb_urb_dir_in(struct urb *urb)
@@ -1590,7 +1594,7 @@
  * usb_urb_dir_out - check if an URB describes an OUT transfer
  * @urb: URB to be checked
  *
- * Returns 1 if @urb describes an OUT transfer (host-to-device),
+ * Return: 1 if @urb describes an OUT transfer (host-to-device),
  * otherwise 0.
  */
 static inline int usb_urb_dir_out(struct urb *urb)