ext4: factor out ext4_load_and_init_journal()

This patch group the journal load and initialize code together and
factor out ext4_load_and_init_journal(). This patch also removes the
lable 'no_journal' which is not needed after refactor.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220916141527.1012715-13-yanaijie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>