mcdb_makefn.c - init m->head=NULL for destructors
mcdb_makefn.c - init m->head=NULL for destructors

mcdb_makefn.c - init m->head=NULL for destructors so that if
mcdb_make_destroy(m) is called along with mcdb_makefn_cleanup(m),
mcdb_make_destroy() will have sane behavior

gstrauss/mcdb,gstrauss/mcdb,gstrauss/mcdb,gstrauss/mcdb,gstrauss/mcdb