ext4: fix lazytime optimization

We had a fencepost error in the lazytime optimization which means that
timestamp would get written to the wrong inode.

Cc: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 55b187c..0554b0b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4345,7 +4345,7 @@
 	int inode_size = EXT4_INODE_SIZE(sb);
 
 	oi.orig_ino = orig_ino;
-	ino = orig_ino & ~(inodes_per_block - 1);
+	ino = (orig_ino & ~(inodes_per_block - 1)) + 1;
 	for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
 		if (ino == orig_ino)
 			continue;