Michael Brown
068ef5f72d
[process] Hold reference to process during call to step()
It is conceivable that the process may terminate during the execution
of step(). If nothing else holds a reference to the containing
object, this would cause the object to be freed prior to returning
from step().
Add a ref_get()/ref_put() around the call to ->step() to prevent this
from happening.
Signed-off-by: Michael Brown <mcb30@ipxe.org>