usb: gadget: ncm: Fix endianness of wMaxSegmentSize variable in ecm_desc

usb: gadget: ncm: Fix endianness of wMaxSegmentSize variable in ecm_desc

Recent commit [1] added support for changing max segment size of the NCM
interface via configfs. But the value of segment size value stored in
ncm_opts need to be converted to little endian before saving it in
ecm_desc. Also while initialising the value of segment size in opts during
instance allocation, the value ETH_FRAME_LEN needs to be assigned directly
without any conversion as ETH_FRAME_LEN and the variable max_segment_size
are native endian. The current implementaion modifies it into little endian
thus breaking things for big endian targets.

Fix endianness while assigning these variables.
While at it, fix up some stray spaces in comments added in code.

[1]: https://lore.kernel.org/all/20231221153216.18657-1-quic_kriskura@quicinc.com/

Fixes: 1900daeefd3e ("usb: gadget: ncm: Add support to update wMaxSegmentSize via configfs")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240118154910.8765-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>