UBI: improve internal interfaces

Pass volume description object to the EBA function which makes
more sense, and EBA function do not have to find the volume
description object by volume ID.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index b85ca18..5d00364 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -249,7 +249,7 @@
 
 	for (i = 0; i < ubi->vtbl_slots; i++)
 		if (ubi->volumes[i])
-			ubi_free_volume(ubi, i);
+			ubi_free_volume(ubi, ubi->volumes[i]);
 }
 
 /**
@@ -300,7 +300,7 @@
 
 	for (i = 0; i < ubi->vtbl_slots; i++)
 		if (ubi->volumes[i]) {
-			err = ubi_add_volume(ubi, i);
+			err = ubi_add_volume(ubi, ubi->volumes[i]);
 			if (err) {
 				ubi_err("cannot add volume %d", i);
 				goto out_volumes;