mmc: omap_hsmmc: release correct resource

res can be one of several resources, as this variable is re-used several
times during probe.  This can cause the wrong resource parameters to be
passed to release_mem_region().

Get the original memory resource before calling release_mem_region().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 4254b6f..d15b149 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -2042,7 +2042,9 @@
 err_alloc:
 	omap_hsmmc_gpio_free(pdata);
 err:
-	release_mem_region(res->start, resource_size(res));
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
 	return ret;
 }