Text tombstone overflow and helpless

Betatesters noticed the death message could overflow the text tombstone,
because the helpless reason was also shown there.

So don't show the helpless at all in the tombstone.  The helpless is
still put in the record, logfile, and as a separate while-field in xlogfile.

src/end.c

@@ -478,12 +478,6 @@ int how;
             Sprintf(eos(buf), " called %s", MNAME(mtmp));
     }
 
-    if (multi) {
-        if (multi_reason)
-            Sprintf(eos(buf), ", while %s", multi_reason);
-        else
-            Strcat(buf, ", while helpless");
-    }
     Strcpy(killer.name, buf);
     if (mptr->mlet == S_WRAITH)
         u.ugrave_arise = PM_WRAITH;