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=1206406Signed-off-by: NShanzhi Yu <shyu@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_driver.c

@@ -16642,6 +16642,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     if (!virStorageSourceIsLocalStorage(mirror)) {
         virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
                        _("non-file destination not supported yet"));
+        goto endjob;
     }
     if (stat(mirror->path, &st) < 0) {
         if (errno != ENOENT) {