thunderbolt: xdomain: Fix 'tb_unregister_service_driver()'s 'drv' param

Fixes the following W=1 kernel build warning(s):

 drivers/thunderbolt/xdomain.c:678: warning: Function parameter or member 'drv' not described in 'tb_unregister_service_driver'
 drivers/thunderbolt/xdomain.c:678: warning: Excess function parameter 'xdrv' description in 'tb_unregister_service_driver'

Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/xdomain.c

@@ -670,7 +670,7 @@ EXPORT_SYMBOL_GPL(tb_register_service_driver);
 
 /**
  * tb_unregister_service_driver() - Unregister XDomain service driver
- * @xdrv: Driver to unregister
+ * @drv: Driver to unregister
  *
  * Unregisters XDomain service driver from the bus.
  */