[Patch]Fix the bug of missing definition of argstr and retstr

[Frank Ch. Eigler]

Cai Fei <caifei@cn.fujitsu.com> writes:

> [...]
> After adding definition of pid and argstr for syscall getpgid, I
> checked the tapset
> for other syscalls. The same problems of missing definition of argstr
> and retstr exist.

There is generally no need to create variables that simply carry empty
strings.  The translator will do that automatically if necessary.

>
> 		kernel.function("sys_getegid")
> {
> 	name = "getegid"
> +	argstr = ""
> }

The only substantial effect of this is to prevent a probe based on
this alias from using "argstr" as a *numeric* variable.


- FChE