greybus: bundle: fix double freeing of bundle structure

The bundle will be released by gb_bundle_release() once all references
for the bundle are dropped. And so there is no need to free it in the
error path specially.

Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>