USB: usb.h: tweak struct urb to remove wasted space

Quoted 6 lines · Oliver Neukum

Quoted 2 lines · Greg Kroah-Hartman

By moving one field around in 'struct urb' we reduce the size of the structure by 8 bytes.

If you are going for this I have to ask why unlink and status are full size ints anyway.

History, they hold a "normal" negative error code. I guess we could turn them into s16, if it really matters, but that feels odd to me.