Set errno = ENOMEM on faild countcheck().

lib/memdebug.c

@@ -95,6 +95,7 @@ static bool countcheck(const char *func, int line, const char *source)
       if(source)
         fprintf(stderr, "LIMIT %s:%d %s reached memlimit\n",
                 source, line, func);
+      errno = ENOMEM;
       return TRUE; /* RETURN ERROR! */
     }
     else