uwb: remove duplicate cpu_to_le16()

These parameters should be passed as cpu endian because we change it to
little endian inside usb_control_msg().  On x86 cpu_to_le16() doesn't
do anything so either way works but I think the original code would break
on big endian systems.

I removed the masks as well because that usb_control_msg() parameters
are __u16 so we already only use the lower bits.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Vrabel <david.vrabel@csr.com>