tests: skip tests if strace is not functional Chances are that strace is available but not functional due to restricted permissions: strace: test_ptrace_get_syscall_info: PTRACE_TRACEME: Operation not permitted strace: ptrace(PTRACE_TRACEME, ...): Operation not permitted +++ exited with 1 +++ Just skip the tests then. Signed-off-by: Christian Hesse <mail@eworm.de>