This reverts commit 7161082c.

Reverting this patch fixes a divide-by-zero error in qemu that can be
fairly reliably triggered by doing block migration. In this case, the
configuration/error was:

source: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios
-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd
boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive
file=disk1.img,if=virtio -drive file=disk2.img,if=virtio -device
virtio-net-pci,netdev=net0 -netdev user,id=net0 -monitor
unix:/tmp/vm-hmp.sock,server,nowait -qmp
unix:/tmp/vm-qmp.sock,server,nowait -vnc :100

16837 Floating point exception(core dumped)

target: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios
-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd
boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive
file=target_disk1.img,if=virtio -drive file=target_disk2.img,if=virtio
-device virtio-net-pci,netdev=net0 -netdev user,id=net0 -incoming
unix:/tmp/migrate.sock -monitor
unix:/tmp/vm-hmp-incoming.sock,server,nowait -qmp
unix:/tmp/vm-qmp-incoming.sock,server,nowait -vnc :101

Receiving block device images
20 %
21 %
load of migration failed

This revert potentially re-introduces a bug that was present in 1.4,
but fixes a prevalent issue with block migration so we should revert
it for now and take an updated patch later.

Conflicts:

	migration.c

* fixed up to remove logic introduced in 7161082c

 while leaving
  changes in HEAD intact

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Message-id: 1368739544-31021-1-git-send-email-mdroth@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>