ceph: add d_drop for some error cases in ceph_mknod()

When file num exceeds quota limit or fails from ceph_per_init_acls()
should call d_drop to drop dentry from cache as well.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/dir.c

@@ -827,12 +827,14 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 	if (ceph_snap(dir) != CEPH_NOSNAP)
 		return -EROFS;
 
-	if (ceph_quota_is_max_files_exceeded(dir))
-		return -EDQUOT;
+	if (ceph_quota_is_max_files_exceeded(dir)) {
+		err = -EDQUOT;
+		goto out;
+	}
 
 	err = ceph_pre_init_acls(dir, &mode, &acls);
 	if (err < 0)
-		return err;
+		goto out;
 
 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
 	     dir, dentry, mode, rdev);