qemu: add the missing jobinfo type in qemuDomainGetJobInfo

Commit 6fcddfcd refactored job statistics but missed the jobinfo type updated
in qemuDomainGetJobInfo. After this patch, we can use virDomainGetJobInfo to
get jobinfo type again.

Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>