[MIPS] iounmap if in vr41xx_pciu_init() pci clock is over 33MHz

iounmap if pci clock is over 33MHz.  Cosmetic because the iomap() in this
case is just a bit of address magic.
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Acked-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/pci/pci-vr41xx.c

@@ -154,6 +154,7 @@ static int __init vr41xx_pciu_init(void)
 		pciu_write(PCICLKSELREG, QUARTER_VTCLOCK);
 	else {
 		printk(KERN_ERR "PCI Clock is over 33MHz.\n");
+		iounmap(pciu_base);
 		return -EINVAL;
 	}