qemu: Don't reset TLS in qemuMigrationRun

qemu: Don't reset TLS in qemuMigrationRun

Finished qemuMigrationRun does not mean the migration itself finished
(it might have just switched to post-copy mode). While resetting TLS
parameters is probably OK at this point even if migration is still
running, we want to consolidate the code which resets various migration
parameters. Thus qemuMigrationResetTLS will be called from the Confirm
phase (or at the end of the Perform phase in case of v2 protocol), when
migration is either canceled or finished.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>