ext4: call ext4_mb_mark_context in ext4_free_blocks_simple

call ext4_mb_mark_context in ext4_free_blocks_simple to:
1. remove repeat code
2. pair update of free_clusters in ext4_mb_new_blocks_simple.
3. add missing ext4_lock_group/ext4_unlock_group protection.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>