staging:serqt_usb2: Fix sparse warning restricted __le16 degrades to integer

This patch fixes the following sparse warning :
drivers/staging/serqt_usb2/serqt_usb2.c:727:40: warning: restricted __le16 degrades to integer

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>