Currently ztailpacking pclusters are chained with FOLLOWED_NOINPLACE and
not recorded into the managed_pslots XArray.
After commit 7674a42f35ea ("erofs: use struct lockref to replace
handcrafted approach"), ztailpacking pclusters won't be freed with
erofs_workgroup_put() anymore, which will cause the following issue:
BUG erofs_pcluster-1 (Tainted: G OE ): Objects remaining in erofs_pcluster-1 on __kmem_cache_shutdown()
Use z_erofs_free_pcluster() directly to free ztailpacking pclusters.
Fixes: 7674a42f35ea ("erofs: use struct lockref to replace handcrafted approach")
Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>