ext4: add trace exit in exception path.

Missing trace exit in exception path of ext4_sync_file and
ext4_ind_map_blocks.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20200921124738.23352-1-zhangqilong3@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>