Description: KVM: X86: Fix scan ioapic use-before-initialization
References:
 https://lkml.org/lkml/2018/11/20/580
Notes:
 carnil> Introduced by 3d81bc7e96d6bca0b8f8b7d1bf6ea72caa3aac57 (3.10-rc1)
 bwh> I'm fairly sure this is impossible before commit 5c919412fe61
 bwh> "kvm/x86: Hyper-V synthetic interrupt controller" (4.5-rc1).  The
 bwh> reproducer didn't work for me on either 3.16 or 4.9.
Bugs:
upstream: released (4.20-rc5) [e97f852fd4561e77721bb9a4e0ea9d98305b1e93]
4.19-upstream-stable: released (4.19.7) [61c42d657c859ccc95e53afdac64f73a0053b8ea]
4.9-upstream-stable: released (4.9.143) [3a468e8e5a6124523e2e94c33866c609cc914876]
3.16-upstream-stable: N/A "Vulnerable code not present"
sid: released (4.19.9-1)
4.9-stretch-security: released (4.9.144-1)
3.16-jessie-security: N/A "Vulnerable code not present"