ocfs2: cleanup trace events

ocfs2: cleanup trace events

After commit 6dc8bc0fb300 ("ocfs2: switch to iter_file_splice_write()"),
ocfs2 has switched from ocfs2_file_splice_write() to
iter_file_splice_write(), so cleanup the corresponding trace event as
well.

Link: https://lkml.kernel.org/r/20230528132033.217664-2-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>