dlm_midcomms_get_mhandle
mh = dlm_midcomms_get_mhandle(to_nodeid, mb_len, &mb);
mh = dlm_midcomms_get_mhandle(node->nodeid, mb_len, &ppc);
struct dlm_mhandle *dlm_midcomms_get_mhandle(int nodeid, int len, char **ppc);
mh = dlm_midcomms_get_mhandle(nodeid, mb_len, &mb);
mh = dlm_midcomms_get_mhandle(to_nodeid, mb_len, &mb);