qemu: Add qemu_killer_report test script

Automate the testcase named "QEMU should report
the PID of the process that sent it kill
signals test case" that sent it kill signals.

Signed-off-by: Feng Yang <fyang@redhat.com>
Acked-by: Xiaoqing Wei <xwei@redhat.com>
Acked-by: Qingtang Zhou <qzhou@redhat.com>