Remove needless memcpys in wooting_usb_send_buffer_v2

[Sainan]

This is basically what I do in my own code and It Just Works™, even tho it looks a bit counterintuitive.

[simon-wh]

Hmmm, it does look like it'll work fine, but it also looks like it's a bit trickier to maintain and for people to immediately understand.
Is the cost of the additional memcpy enough to make it worth it?

[Sainan]

Well, the cost if 4 memcpys per packet to send. It's your decision.