mwifiex: propagate sdio_enable_func() errno code in mwifiex_sdio_probe()

If the sdio_enable_func() function fails on .probe, the -EIO errno code
is always returned but that could make more difficult to debug and find
the cause of why the function actually failed.

Since the driver/device core prints the value returned by .probe in its
error message propagate what was returned by sdio_enable_func() at fail.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/sdio.c

@@ -184,7 +184,7 @@ mwifiex_sdio_probe(struct sdio_func *func, const struct sdio_device_id *id)
 	if (ret) {
 		pr_err("%s: failed to enable function\n", __func__);
 		kfree(card);
-		return -EIO;
+		return ret;
 	}
 
 	/* device tree node parsing and platform specific configuration*/