fix analyzer complaint

about testing whether an unsigned value is >= 0.  Since there's no
chance that it might have a value of NON_PM (-1), just comment out
the assertion that was intended to ward off a potential complaint
about that.

src/do_name.c

@@ -898,7 +898,7 @@ x_monnam(
 
     /* 'pm_name' is the base part of most names */
     if (do_mappear) {
-        assert(ismnum(mtmp->mappearance));
+        /*assert(ismnum(mtmp->mappearance));*/
         pm_name = pmname(&mons[mtmp->mappearance], Mgender(mtmp));
     } else {
         pm_name = mon_pmname(mtmp);