prctl-seccomp-strict.test: robustify against unrelated prctl invocations
prctl-seccomp-strict.test: robustify against unrelated prctl invocations

* tests/prctl-seccomp-strict.test: Filter out PR_GET_* prctl calls.

Saruta/strace,cuviper/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace