UBIFS: switch to ubifs_leb_read

Instead of using 'ubi_read()' function directly, used the 'ubifs_leb_read()'
helper function instead. This allows to get rid of several redundant error
messages and make sure that we always have a stack dump on read errors.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/scan.c b/fs/ubifs/scan.c
index c7df916..37383e8 100644
--- a/fs/ubifs/scan.c
+++ b/fs/ubifs/scan.c
@@ -148,7 +148,7 @@
 	INIT_LIST_HEAD(&sleb->nodes);
 	sleb->buf = sbuf;
 
-	err = ubi_read(c->ubi, lnum, sbuf + offs, offs, c->leb_size - offs);
+	err = ubifs_leb_read(c, lnum, sbuf + offs, offs, c->leb_size - offs, 0);
 	if (err && err != -EBADMSG) {
 		ubifs_err("cannot read %d bytes from LEB %d:%d,"
 			  " error %d", c->leb_size - offs, lnum, offs, err);