net: cdc_ncm: GetNtbFormat endian fix

The GetNtbFormat and SetNtbFormat requests operate on 16 bit little
endian values. We get away with ignoring this most of the time, because
we only care about USB_CDC_NCM_NTB16_FORMAT which is 0x0000.  This
fails for USB_CDC_NCM_NTB32_FORMAT.

Fix comparison between LE value from device and constant by converting
the constant to LE.

Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Fixes: 2b02c20c

 ("cdc_ncm: Set NTB format again after altsetting switch for Huawei devices")
Cc: Enrico Mioso <mrkiko.rs@gmail.com>
Cc: Christian Panton <christian@panton.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-By: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>