fix access nil table

Also move some print into kp_wait

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
update test/tracepoint.kp

Prepare to kill os.sleep, all user of os.sleep should use timer.s/ms

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
fix print string when error happens

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
use kp_exit after error happened

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
use unified kp_error to make error indication

kill old kp_runerror

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
let ktap wait if there have timer in scripts

keep the same logic as tracing does.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
update test/timer.kp

Prepare to kill os.sleep

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
kill os.sleep in testsuite

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
kill os library

Since only function in os library os.sleep already end
its life, so remove os library.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
kill e.format

e.format exist in there for no reason, user could
read /sys/kernel/debug/tracing/events/*/*/format,
so remove e.format.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>