When allocating the IPv6 header to stick in front of raw packet being sent via a raw IPv6 socket, use M_DONTWAIT not M_TRYWAIT, as we're holding the raw pcb mutex.
When allocating the IPv6 header to stick in front of raw packet being
sent via a raw IPv6 socket, use M_DONTWAIT not M_TRYWAIT, as we're
holding the raw pcb mutex.

Reported, tested by:	kuriyama

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase