jbd2: remove unused t_handle_lock

Since commit f7f497cb7024 ("jbd2: kill t_handle_lock
transaction spinlock"), this lock has been no use.

Fixes: f7f497cb7024 ("jbd2: kill t_handle_lock transaction spinlock")
Signed-off-by: Wang Jianjian <[e-mail]>
Reviewed-by: Ritesh Harjani (IBM) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Theodore Ts'o <[e-mail]>

include/linux/jbd2.h

···
 	struct list_head	t_inode_list;
 
 	/*
-	 * Protects info related to handles
-	 */
-	spinlock_t		t_handle_lock;
-
-	/*
 	 * Longest time some handle had to wait for running transaction
 	 */
 	unsigned long		t_max_wait;