seccomp: adding getrusage to the whitelist

getrusage is used in a number of places throughout the qemu codebase
(notably, in crypto/pbkdf.c).  Without this syscall being whitelisted,
qemu ends up getting killed by the kernel whenever you try to connect to
a VNC console.

Signed-off-by: Brian Rak <brak@gameservers.com>
Acked-by: Eduardo Otubo <eduardo.otubo@profitbricks.com>

qemu-seccomp.c

@@ -65,6 +65,7 @@ static const struct QemuSeccompSyscall seccomp_whitelist[] = {
     { SCMP_SYS(prctl), 245 },
     { SCMP_SYS(signalfd), 245 },
     { SCMP_SYS(getrlimit), 245 },
+    { SCMP_SYS(getrusage), 245 },
     { SCMP_SYS(set_tid_address), 245 },
     { SCMP_SYS(statfs), 245 },
     { SCMP_SYS(unlink), 245 },