jbd2: drop declaration of journal_sync_buffer()

The journal_sync_buffer() function was never carried over from jbd to
jbd2.  So get rid of the vestigal declaration of this (non-existent)
function.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>

fs/jbd2/journal.c

@@ -66,9 +66,6 @@ EXPORT_SYMBOL(jbd2_journal_get_undo_access);
 EXPORT_SYMBOL(jbd2_journal_set_triggers);
 EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
 EXPORT_SYMBOL(jbd2_journal_forget);
-#if 0
-EXPORT_SYMBOL(journal_sync_buffer);
-#endif
 EXPORT_SYMBOL(jbd2_journal_flush);
 EXPORT_SYMBOL(jbd2_journal_revoke);
 

include/linux/jbd2.h

@@ -1373,7 +1373,6 @@ void		 jbd2_journal_set_triggers(struct buffer_head *,
 					   struct jbd2_buffer_trigger_type *type);
 extern int	 jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
 extern int	 jbd2_journal_forget (handle_t *, struct buffer_head *);
-extern void	 journal_sync_buffer (struct buffer_head *);
 extern int	 jbd2_journal_invalidatepage(journal_t *,
 				struct page *, unsigned int, unsigned int);
 extern int	 jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);