usb: core: hcd: change sizeof(vaddr) to sizeof(unsigned long)

`vaddr` is a pointer to unsigned char. sizeof(vaddr) here intends
to get the size of a pointer. But readers may get confused. Change
sizeof(vaddr) to sizeof(unsigned long) makes more sense.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Link: https://lore.kernel.org/r/20211209062441.9856-1-guozhengkui@vivo.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd.c

@@ -1281,7 +1281,7 @@ static int hcd_alloc_coherent(struct usb_bus *bus,
 		return -EFAULT;
 	}
 
-	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
+	vaddr = hcd_buffer_alloc(bus, size + sizeof(unsigned long),
 				 mem_flags, dma_handle);
 	if (!vaddr)
 		return -ENOMEM;