staging: r8712u: Fix Sparse warnings in rtl871x_ioctl_linux.c

Sparse reports the following:
  CHECK   drivers/staging/rtl8712/rtl871x_ioctl_linux.c
drivers/staging/rtl8712/rtl871x_ioctl_linux.c:1422:46: warning: restricted __le16 degrades to integer
drivers/staging/rtl8712/rtl871x_ioctl_linux.c:1424:46: warning: restricted __le16 degrades to integer

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>