[IPV4]: Remove suprious use of goto out: in icmp_reply

This seems to be an artifact of the follwoing commit in February '02.

e7e173af42dbf37b1d946f9ee00219cb3b2bea6a

In a nutshell, goto out and return actually do the same thing,
and both are called in this function. This patch removes out.

Signed-Off-By: Horms <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>