Set a maximum message timeout on the next MsgSend
#include <qvm/utils.h>
int qvm_msgblock_oneshot(const vdev_t *vdp, unsigned mult)
This function sets the maximum message time for the next MsgSend (i.e., a single MsgSend) only.
To set the maximum message time for a block of multiple MsgSends, call qvm_msgblock_start().
EOK if successful; otherwise an errno value.