erofs: do sanity check on m->type in z_erofs_load_compact_lcluster()

erofs: do sanity check on m->type in z_erofs_load_compact_lcluster()

All below functions will do sanity check on m->type, let's move sanity
check to z_erofs_load_compact_lcluster() for cleanup.
- z_erofs_map_blocks_fo
- z_erofs_get_extent_compressedlen
- z_erofs_get_extent_decompressedlen
- z_erofs_extent_lookback

Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250708110928.3110375-1-chao@kernel.org
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>