net/packet: fix overflow in check for tp_reserve

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.

Change-Id: Ia1714c2f7d39fec33ee38b4a4f23a6ea6aa89216
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: bcc5364bdcfe131e6379363f089e7b4108d35b70
Signed-off-by: Dennis Cagle <dcagle@codeaurora.org>