Add "spinlock.h", which was included indirectly, and sort includes in
alphabet order.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200106013416.9604-8-digetx@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>