Commit 7449fb36 ("migration/save: pass checkpointed_stream from libxl to
libxc ") failed to initialise rc in the error path.
Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>