[Virtio-fs] [PATCH] virtiofsd: Add `sigreturn` to the seccomp whitelist

[Stefan Hajnoczi]

To find out:
# perf record -e signal:signal_deliver
...wait for QEMU shutdown...
^C
# perf script
qemu-system-x86_64 2319136 [001] 1062886.415312:
signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=7fc6ccfbabc0
sa_flags=14000004

sig=2 is SIGINT. This is just an example, I didn't run virtiofsd.