seccomp: arm64/x32 do not have _sysctl

seccomp: arm64/x32 do not have _sysctl

So don't even try to added the filter to reduce noise.
The test is updated to skip calling _sysctl because the kernel prints
an oops-like message that is confusing and unhelpful:

Jul 15 21:07:01 rpi3 kernel: test-seccomp[8448]: syscall -10080
Jul 15 21:07:01 rpi3 kernel: Code: aa0503e4 aa0603e5 aa0703e6 d4000001 (b13ffc1f)
Jul 15 21:07:01 rpi3 kernel: CPU: 3 PID: 8448 Comm: test-seccomp Tainted: G        W       4.11.8-300.fc26.aarch64 #1
Jul 15 21:07:01 rpi3 kernel: Hardware name: raspberrypi rpi/rpi, BIOS 2017.05 06/24/2017
Jul 15 21:07:01 rpi3 kernel: task: ffff80002bb0bb00 task.stack: ffff800036354000
Jul 15 21:07:01 rpi3 kernel: PC is at 0xffff8669c7c4
Jul 15 21:07:01 rpi3 kernel: LR is at 0xaaaac64b6750
Jul 15 21:07:01 rpi3 kernel: pc : [<0000ffff8669c7c4>] lr : [<0000aaaac64b6750>] pstate: 60000000
Jul 15 21:07:01 rpi3 kernel: sp : 0000ffffdc640fd0
Jul 15 21:07:01 rpi3 kernel: x29: 0000ffffdc640fd0 x28: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x27: 0000000000000000 x26: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x25: 0000000000000000 x24: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x23: 0000000000000000 x22: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x21: 0000aaaac64b4940 x20: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x19: 0000aaaac64b88f8 x18: 0000000000000020
Jul 15 21:07:01 rpi3 kernel: x17: 0000ffff8669c7a0 x16: 0000aaaac64d2ee0
Jul 15 21:07:01 rpi3 kernel: x15: 0000000000000000 x14: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x13: 203a657275746365 x12: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x11: 0000ffffdc640418 x10: 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x9 : 0000000000000005 x8 : 00000000ffffd8a0
Jul 15 21:07:01 rpi3 kernel: x7 : 7f7f7f7f7f7f7f7f x6 : 7f7f7f7f7f7f7f7f
Jul 15 21:07:01 rpi3 kernel: x5 : 65736d68716f7277 x4 : 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x3 : 0000000000000008 x2 : 0000000000000000
Jul 15 21:07:01 rpi3 kernel: x1 : 0000000000000000 x0 : 0000000000000000
Jul 15 21:07:01 rpi3 kernel:

(cherry picked from commit 1e20e640132c700c23494bb9e2619afb83878380)