mmc: Register debugfs dir before calling card probe function.

This way, the probe function may register debugfs files if it wants to.
This fixes a bug with mmc_test where mmc_test_register_file_test() is
called before the card's debugfs dir exists, and so it fails.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Tested-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

drivers/mmc/core/bus.c

@@ -303,14 +303,14 @@ int mmc_add_card(struct mmc_card *card)
 			type, card->rca);
 	}
 
-	ret = device_add(&card->dev);
-	if (ret)
-		return ret;
-
 #ifdef CONFIG_DEBUG_FS
 	mmc_add_card_debugfs(card);
 #endif
 
+	ret = device_add(&card->dev);
+	if (ret)
+		return ret;
+
 	mmc_card_set_present(card);
 
 	return 0;