tcp: call sock_orphan() before freeing socket in tcp_nuke_addr

Ensure socket is marked as dead prior to freeing it. This will
prevent other tasks executing in the system from potentially
using the freed resource.

Change-Id: I3c7c3ce24f287c4ea7ca7c1d1e5dc96ad37596b0
Signed-off-by: Osvaldo Banuelos <osvaldob@codeaurora.org>