fs/jbd: Export log_start_commit to fix ext3 build.

This fixes:
ERROR: "log_start_commit" [fs/ext3/ext3.ko] undefined!
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

fs/jbd/journal.c

@@ -73,6 +73,7 @@ EXPORT_SYMBOL(journal_errno);
 EXPORT_SYMBOL(journal_ack_err);
 EXPORT_SYMBOL(journal_clear_err);
 EXPORT_SYMBOL(log_wait_commit);
+EXPORT_SYMBOL(log_start_commit);
 EXPORT_SYMBOL(journal_start_commit);
 EXPORT_SYMBOL(journal_force_commit_nested);
 EXPORT_SYMBOL(journal_wipe);