qemu: end the job when try to blockcopy to non-file destination
Blockcopy to non-file destination is not supported according the code,
but a 'goto endjob' is missed after checking the destination.
This leads to calling drive-mirror with wrong parameters.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1206406
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>