jbd2: Annotate transaction start also for jbd2_journal_restart()

lockdep annotation for a transaction start has been at the end of
jbd2_journal_start(). But a transaction is also started from
jbd2_journal_restart(). Move the lockdep annotation to start_this_handle()
which covers both cases.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>