ext4: get rid of ppath in ext4_force_split_extent_at()

ext4: get rid of ppath in ext4_force_split_extent_at()

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_force_split_extent_at(), the following is
done here:

 * Free the extents path when an error is encountered.

No functional changes.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-17-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>