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/misc.c b/drivers/mtd/ubi/misc.c
index 9e2338c..93e0528 100644
--- a/drivers/mtd/ubi/misc.c
+++ b/drivers/mtd/ubi/misc.c
@@ -79,7 +79,7 @@
 		else
 			size = vol->usable_leb_size;
 
-		err = ubi_eba_read_leb(ubi, vol_id, i, buf, 0, size, 1);
+		err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
 		if (err) {
 			if (err == -EBADMSG)
 				err = 1;