UBIFS: fix error handling in dump_lpt_leb()

This patch checks the return value of 'ubifs_unpack_nnode()'.
If this function returns an error, 'nnode' may not be
initialized, so just print an error message and break.
Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

fs/ubifs/lpt_commit.c

@@ -1941,6 +1941,11 @@ static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
 				pr_err("LEB %d:%d, nnode, ",
 				       lnum, offs);
 			err = ubifs_unpack_nnode(c, p, &nnode);
+			if (err) {
+				pr_err("failed to unpack_node, error %d\n",
+				       err);
+				break;
+			}
 			for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 				pr_cont("%d:%d", nnode.nbranch[i].lnum,
 				       nnode.nbranch[i].offs);