erofs: remove unused tag argument while registering a workgroup

All workgroups are registered with tag value set to 0, to simplify
erofs_register_workgroup() interface the tag argument can be removed,
if its only value is sent down to the function body.
Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com>
Link: https://lore.kernel.org/r/20200102120118.14979-3-vladimir@tuxera.comReviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

fs/erofs/internal.h

@@ -403,7 +403,7 @@ int erofs_workgroup_put(struct erofs_workgroup *grp);
 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 					     pgoff_t index);
 int erofs_register_workgroup(struct super_block *sb,
-			     struct erofs_workgroup *grp, bool tag);
+			     struct erofs_workgroup *grp);
 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
 void erofs_shrinker_register(struct super_block *sb);
 void erofs_shrinker_unregister(struct super_block *sb);

fs/erofs/utils.c

@@ -83,8 +83,7 @@ struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 }
 
 int erofs_register_workgroup(struct super_block *sb,
-			     struct erofs_workgroup *grp,
-			     bool tag)
+			     struct erofs_workgroup *grp)
 {
 	struct erofs_sb_info *sbi;
 	int err;
@@ -102,7 +101,7 @@ int erofs_register_workgroup(struct super_block *sb,
 	sbi = EROFS_SB(sb);
 	xa_lock(&sbi->workstn_tree);
 
-	grp = xa_tag_pointer(grp, tag);
+	grp = xa_tag_pointer(grp, 0);
 
 	/*
 	 * Bump up reference count before making this workgroup

fs/erofs/zdata.c

@@ -437,7 +437,7 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
 	 */
 	mutex_trylock(&cl->lock);
 
-	err = erofs_register_workgroup(inode->i_sb, &pcl->obj, 0);
+	err = erofs_register_workgroup(inode->i_sb, &pcl->obj);
 	if (err) {
 		mutex_unlock(&cl->lock);
 		kmem_cache_free(pcluster_cachep, pcl);