ext4: remove unused variable in ext4_get_parent

Signed-off-by: NChristoph Hellwig <hch@lst.de>
[ All users removed in "switch all filesystems over to d_obtain_alias",
  aka commit 44003728 ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/ext4/namei.c

@@ -1061,7 +1061,6 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
 struct dentry *ext4_get_parent(struct dentry *child)
 {
 	unsigned long ino;
-	struct dentry *parent;
 	struct inode *inode;
 	static const struct qstr dotdot = {
 		.name = "..",