ntb: idt: Fix the cacography in ntb_hw_idt.c

The word 'swtich' is wrong, so fix it.
Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

drivers/ntb/hw/idt/ntb_hw_idt.c

@@ -2547,7 +2547,7 @@ static void idt_deinit_dbgfs(struct idt_ntb_dev *ndev)
  */
 
 /*
- * idt_check_setup() - Check whether the IDT PCIe-swtich is properly
+ * idt_check_setup() - Check whether the IDT PCIe-switch is properly
  *		       pre-initialized
  * @pdev:	Pointer to the PCI device descriptor
  *