The variable is not written anymore.

This cleans up after 9e1c2ec8 (which accidentally left variable
pc_sysfw_flash_vs_rom_bug_compatible behind, value always zero), and
buries dead code from commit dafb82e0 (which resurrected the pc_sysfw
code for pc_sysfw_flash_vs_rom_bug_compatible by mistake).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1376069702-22330-2-git-send-email-aliguori@us.ibm.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>