mm: swap: replace cluster_swap_free_nr() with swap_entries_put_[map/cache]()

Replace cluster_swap_free_nr() with swap_entries_put_[map/cache]() to
remove repeat code and leverage batch-remove for entries with last flag. 
After removing cluster_swap_free_nr, only functions with "_nr" suffix
could free entries spanning cross clusters.  Add corresponding description
in comment of swap_entries_put_map_nr() as is first function with "_nr"
suffix and have a non-suffix variant function swap_entries_put_map().

Link: https://lkml.kernel.org/r/20250325162528.68385-9-shikemeng@huaweicloud.com


Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>