mmc: possible leak in mmc_read_ext_csd

The exception path associated with an invalid ext_csd_struct returns
without freeing ext_csd.

Coverity CID 1909.

Signed-off-by: Florin Malita
Signed-off-by: Pierre Ossman <[e-mail]>

drivers/mmc/core/mmc.c

···
 		printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
 			"version %d\n", mmc_hostname(card->host),
 			ext_csd_struct);
-		return -EINVAL;
+		err = -EINVAL;
+		goto out;
 	}
 
 	if (ext_csd_struct >= 2) {