Since 3c75945fd ("netstack: remove PacketBuffer.IsNil()") this has been
invalid. Follow the replacement pattern of that commit.
The old definition inlined to the same code anyway:
func (pk *PacketBuffer) IsNil() bool {
return pk == nil
}
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Jason A. Donenfeld
e3c1354d27