USB: legousbtower: drop redundant endianness comments

The endianness is already encoded in the type specifier so drop the
redundant little-endian comments from the message structs.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105084152.16322-12-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>