These structs are never used to represent the bytes that go over the
network. The big-endian network data is built into a uint8_t array
in nbd_{receive,send}_{request,reply}. Remove the unused magic field,
reorder the struct to avoid holes, and remove the packed attribute.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
56af2dda98