libpcap: add upstream patch to fix runtime issue when TPACKET_V3 isn't supported

libpcap would fail to initialize on Linux when compiled against kernel
headers with TPACKET_V3 support but running on kernel without:

"can't get TPACKET_V3 header len on packet socket: Invalid argument"

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>