staging/ozwpan: coding style __constant_

This fixes the following issues detected by checkpatch.pl:

 WARNING: __constant_cpu_to_le16 should be cpu_to_le16
 #1991: FILE: drivers/staging/ozwpan/ozhcd.c:1991:
 +                      __constant_cpu_to_le16(0x0001);

 WARNING: __constant_cpu_to_le32 should be cpu_to_le32
 #2185: FILE: drivers/staging/ozwpan/ozhcd.c:2185:
 +              put_unaligned(__constant_cpu_to_le32(0), (__le32 *)buf);

 WARNING: __constant_htons should be htons
 #675: FILE: drivers/staging/ozwpan/ozproto.c:675:
 +      binding->ptype.type = __constant_htons(OZ_ETHERTYPE);

Signed-off-by: Jerome Pinot <ngc891@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>