Fix checkpatch.pl CHECK as follows:
CHECK: spinlock_t definition without comment
+       spinlock_t xfer_lock;
Signed-off-by: NBitan Biswas <bbiswas@nvidia.com>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>