Merge branch 'tcp-fix-possible-crash-in-tcp_v4_err'

Eric Dumazet says:

====================
tcp: fix possible crash in tcp_v4_err()

soukjin bae reported a crash in tcp_v4_err() that we
root caused to a missing initialization.

Second patch adds a sanity check in tcp_v4_err() to avoid
future potential problems. Ignoring an ICMP message
is probably better than crashing a machine.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>