ares_striendstr: fix so non-NULL return can happen

This looks to have been broken since it was first introduced in 2005 in
commit aba0b775ea ("Added ares_getnameinfo which mimics the
getnameinfo API")

ares_getnameinfo.c

@@ -417,7 +417,5 @@ static char *ares_striendstr(const char *s1, const char *s2)
           c2++;
         }
     }
-  if (c2 == c1 && c2 == NULL)
-    return (char *)c1_begin;
-  return NULL;
+  return (char *)c1_begin;
 }