btrfs: qgroup: fix a typo in a comment

Add a missing 'r'.  s/qgoup/qgroup/ . Codespell does not catch that for
some reason.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/qgroup.c

@@ -275,7 +275,7 @@ static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *p
 }
 
 /*
- * Add relation specified by two qgoup ids.
+ * Add relation specified by two qgroup ids.
  *
  * Must be called with qgroup_lock held.
  *