mmc: omap: fix error return code

Return a negative error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/omap.c

@@ -1420,8 +1420,10 @@ static int mmc_omap_probe(struct platform_device *pdev)
 	host->reg_shift = (mmc_omap7xx() ? 1 : 2);
 
 	host->mmc_omap_wq = alloc_workqueue("mmc_omap", 0, 0);
-	if (!host->mmc_omap_wq)
+	if (!host->mmc_omap_wq) {
+		ret = -ENOMEM;
 		goto err_plat_cleanup;
+	}
 
 	for (i = 0; i < pdata->nr_slots; i++) {
 		ret = mmc_omap_new_slot(host, i);