ext4: fix potential htree corruption when growing large_dir directories

commit 877ba3f7 upstream.

Commit b5776e75 ("ext4: fix potential htree index checksum
corruption) removed a required restart when multiple levels of index
nodes need to be split.  Fix this to avoid directory htree corruptions
when using the large_dir feature.

Cc: stable@kernel.org # v5.11
Cc: Благодаренко Артём <artem.blagodarenko@gmail.com>
Fixes: b5776e75

 ("ext4: fix potential htree index checksum corruption)
Reported-by: Denis <denis@voxelsoft.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>