spi: omap-uwire: add missing iounmap

This fixes the following coccicheck warning:
linux-2.6/drivers/spi/spi-omap-uwire.c:485:2-8: ERROR: missing iounmap; ioremap on line 471 and execution via conditional on line 481

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-omap-uwire.c b/drivers/spi/spi-omap-uwire.c
index f5176bb..31ce92f 100644
--- a/drivers/spi/spi-omap-uwire.c
+++ b/drivers/spi/spi-omap-uwire.c
@@ -478,6 +478,7 @@
 		status = PTR_ERR(uwire->ck);
 		dev_dbg(&pdev->dev, "no functional clock?\n");
 		spi_master_put(master);
+		iounmap(uwire_base);
 		return status;
 	}
 	clk_enable(uwire->ck);