rfkill: fix minor typo in kernel doc

Fix a minor typo in an exported function documentation
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/rfkill/rfkill.c

@@ -412,7 +412,7 @@ int rfkill_register(struct rfkill *rfkill)
 EXPORT_SYMBOL(rfkill_register);
 
 /**
- * rfkill_unregister - Uegister a rfkill structure.
+ * rfkill_unregister - Unregister a rfkill structure.
  * @rfkill: rfkill structure to be unregistered
  *
  * This function should be called by the network driver during device