net: fix iterating over hashtable in tcp_nuke_addr()

The actual size of the tcp hashinfo table is tcp_hashinfo.ehash_mask + 1
so we need to adjust the loop accordingly to get the sockets hashed into
the last bucket.

Change-Id: I796b3c7b4a1a7fa35fba9e5192a4a403eb6e17de
Signed-off-by: Dmitry Torokhov <dtor@google.com>