seccomp: add kill() to the syscall whitelist

The kill() syscall is triggered with the following command:

 # qemu -sandbox on -monitor stdio \
        -device intel-hda -device hda-duplex -vnc :0

The resulting syslog/audit message:

 # ausearch -m SECCOMP
 ----
 time->Wed Nov 20 09:52:08 2013
 type=SECCOMP msg=audit(1384912328.482:6656): auid=0 uid=0 gid=0 ses=854
  subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=12087
  comm="qemu-kvm" sig=31 syscall=62 compat=0 ip=0x7f7a1d2abc67 code=0x0
 # scmp_sys_resolver 62
 kill

Reported-by: CongLi <coli@redhat.com>
Tested-by: CongLi <coli@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eduardo Otubo <otubo@linux.vnet.ibm.com>
(cherry picked from commit e9eecb5b)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>