add syscalls-demo.sh

this new demo is based on probe-by-id.kp

All syscall tracepoints is passed by ids
change argument passing for ktap script

Now we can pass string argument into ktap script

ktap *.kp "1 2 3"

Then arg[1] will be a string "1 2 3",
not arg[1] = 1, arg[2] = 2, arg[3] = 3

kdebug.probe_by_id also changed, first argument is string type,
not int type.

kdebug.probe_by_id("1 2 3", eventfun)

The reason for this change is target on all tracepoints tracing,
in those case, one int argument is not meet requirement, also we
cannot pass too many argument into kdebug.probe_by_id, that will
consume too much stack, so we use string type as first argument.

See some demo in scripts, it shows how to use this new feature.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
update demo based on probe-by-id.kp

since first argument in probe_by_id is already changed to
string type, update scripts which used on it.

Also add a new syscallls-demo.sh to perform how to trace
syscalls by ids