usb: hub: usb_ext_cap_descriptor.bmAttributes is le32

Better check the correct bit on big endian systems too. Shuts
up the following sparse __CHECK_ENDIAN__ warning:

  .../hub.c:3965:32: warning: restricted __le32 degrades to integer

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>