USB: ohci-sm501: Add missed iounmap() in remove

This driver misses calling iounmap() in remove to undo the ioremap()
called in probe.
Add the missed call to fix it.

Fixes: f54aab6e ("usb: ohci-sm501 driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20200610024844.3628408-1-hslester96@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ohci-sm501.c

@@ -191,6 +191,7 @@ static int ohci_hcd_sm501_drv_remove(struct platform_device *pdev)
 	struct resource	*mem;
 
 	usb_remove_hcd(hcd);
+	iounmap(hcd->regs);
 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
 	usb_put_hcd(hcd);
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);