Fix DEBUG_4ti2 build: Replace lp->it_cnt by lpx_get_int_parm

[mkoeppe]

From Jerry James for Fedora:

there is a bug in the patch, but only for debug builds. Where the old version had:

  lpx_get_int_parm(lp, LPX_K_ITCNT)

the patched version has:

  lp->it_cnt

which is only correct if the compiler can see the structure definition. By default, that is not the case; it is an opaque type. I complained to glpk upstream about the lack of a way to get this information with the new API. I was promised that the next release of glpk will have a function glp_get_it_cnt() to retrieve it. However, that next release hasn't happened yet. Anyway, if you want those DEBUG_4ti2() forms to compile correctly, you'll have to arrange to see the internal structure for now, then migrate to glp_get_it_cnt() once it is actually available, or patch your copy of glpk to add glp_get_it_cnt(). We did the latter for Fedora, with the attached patch. It guards the new function with FEDORA_GLPK_ITCNT to avoid compatibility problems; you probably don't want that.