media: cx18: make v4l2_file_operations const

Make this const as it is only stored in a const field of a
video_device structure.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/cx18/cx18-streams.c

@@ -31,7 +31,7 @@
 
 #define CX18_DSP0_INTERRUPT_MASK     	0xd0004C
 
-static struct v4l2_file_operations cx18_v4l2_enc_fops = {
+static const struct v4l2_file_operations cx18_v4l2_enc_fops = {
 	.owner = THIS_MODULE,
 	.read = cx18_v4l2_read,
 	.open = cx18_v4l2_open,