jbd2: fix kernel-doc notation warning

Fix kernel-doc warning by inserting a beginning '*' character
for the kernel-doc line.

../include/linux/jbd2.h:461: warning: bad line:         journal. These are dirty buffers and revoke descriptor blocks.

Link: https://lore.kernel.org/r/53e3ce27-ceae-560d-0fd4-f95728a33e12@infradead.org
Cc: stable@kernel.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

include/linux/jbd2.h

@@ -457,7 +457,7 @@ struct jbd2_revoke_table_s;
  * @h_journal: Which journal handle belongs to - used iff h_reserved set.
  * @h_rsv_handle: Handle reserved for finishing the logical operation.
  * @h_total_credits: Number of remaining buffers we are allowed to add to
-	journal. These are dirty buffers and revoke descriptor blocks.
+ *	journal. These are dirty buffers and revoke descriptor blocks.
  * @h_revoke_credits: Number of remaining revoke records available for handle
  * @h_ref: Reference count on this handle.
  * @h_err: Field for caller's use to track errors through large fs operations.