staging: ks7010: fix error handling in ks7010_upload_firmware

This commit checks missing error code check when checking
if the firmware is running reading General Communication
Register A (GCR_A).

It also set ret to EBUSY if firmware is running before
copying it.
Signed-off-by: NSergio Paracuellos <sergio.paracuellos@gmail.com>
Reviewed-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ks7010/ks7010_sdio.c

@@ -657,8 +657,11 @@ static int ks7010_upload_firmware(struct ks_sdio_card *card)
 
 	/* Firmware running ? */
 	ret = ks7010_sdio_readb(priv, GCR_A, &byte);
+	if (ret)
+		goto release_host_and_free;
 	if (byte == GCR_A_RUN) {
 		netdev_dbg(priv->net_dev, "MAC firmware running ...\n");
+		ret = -EBUSY;
 		goto release_host_and_free;
 	}