Revert "selftests/ftrace: Update synthetic event syntax errors"

This reverts commit 31c2e369 which is commit
b5734e99 upstream.

The reverted commit belongs to patchset which updated synthetic event
command parsing and testcase 'trigger-synthetic_event_syntax_errors.tc'
Link: https://lore.kernel.org/all/20210211020950.102294806@goodmis.org/

However this testcase update was backported alone without feature
update, which makes the testcase cannot pass on stable branch.

Revert this commit to make the testcase correct.

Fixes: 31c2e369

 ("selftests/ftrace: Update synthetic event syntax errors")
Reported-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>