bridge: Do not compile options in br_parse_ip_options

bridge: Do not compile options in br_parse_ip_options

Commit 70ab905bdb5fb08c7c871b1b7e8b74ced2110966

	bridge : Sanitize skb before it enters the IP stack

broke when IP options are actually used because it mangles the
skb as if it entered the IP stack which is wrong because the
bridge is supposed to operate below the IP stack.

Since nobody has actually requested for parsing of IP options
this patch fixes it by simply reverting to the previous approach
of ignoring all IP options, i.e., zeroing the IPCB.

If and when somebody who uses IP options and actually needs them
to be parsed by the bridge complains then we can revisit this.

Reported-by: David Newall <davidn@davidnewall.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>