staging: vt6655: ioctl.h: Replace C99 // comment by /* */

Replace C99 "//" comment by "/* */"
Signed-off-by: NVeronika Kabatova <veronicca114@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6655/ioctl.h

@@ -33,4 +33,4 @@
 
 int private_ioctl(struct vnt_private *, struct ifreq *rq);
 
-#endif // __IOCTL_H__
+#endif /* __IOCTL_H__ */