V4L/DVB (9193): stk-webcam: minor cleanup

This patch:
1) removes the unnecessary kref.h include file
2) removes unnecessary pointer validation from read and poll routines.
(Neither poll nor read may be called unless a call to open succeeds. A
successful call to open will always set the file private_data pointer.
Verifying that it is not null is therefore unnecessary. The associated
release and mmap calls currently ignore this check.)
3) adds a space to syslog output.
4) removes an unused function prototype.

Signed-off-by: David Ellingsworth <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/video/stk-webcam.c

···
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
-#include <linux/kref.h>
 
 #include <linux/usb.h>
 #include <linux/mm.h>
···
 	struct stk_sio_buffer *sbuf;
 	struct stk_camera *dev = fp->private_data;
 
-	if (dev == NULL)
-		return -EIO;
-
 	if (!is_present(dev))
 		return -EIO;
 	if (dev->owner && dev->owner != fp)
···
 static unsigned int v4l_stk_poll(struct file *fp, poll_table *wait)
 {
 	struct stk_camera *dev = fp->private_data;
-
-	if (dev == NULL)
-		return -ENODEV;
 
 	poll_wait(fp, &dev->wait_frame, wait);
 
···
 	wake_up_interruptible(&dev->wait_frame);
 	stk_remove_sysfs_files(&dev->vdev);
 
-	STK_INFO("Syntek USB2.0 Camera release resources"
+	STK_INFO("Syntek USB2.0 Camera release resources "
 		"video device /dev/video%d\n", dev->vdev.minor);
 
 	video_unregister_device(&dev->vdev);

drivers/media/video/stk-webcam.h

···
 
 #define vdev_to_camera(d) container_of(d, struct stk_camera, vdev)
 
-void stk_camera_delete(struct kref *);
 int stk_camera_write_reg(struct stk_camera *, u16, u8);
 int stk_camera_read_reg(struct stk_camera *, u16, int *);