Fix incorrect conditional usage of .owner

The examples code wrapped .owner = THIS_MODULE inside version checks,
suggesting that it is no longer needed after v6.4. This is only true
for driver types where the driver core sets .owner automatically (e.g.
platform and i2c drivers).

For structures such as struct file_operations, .owner must still be set
explicitly by the user. Without it, module reference counting will be
broken, allowing a module to be unloaded while still in use, which can
lead to kernel panics.

For struct class, the core can safely omit .owner, but explicitly
setting it remains correct and safe. Adding conditional #if checks
around it only makes the examples harder to read and more confusing for
readers.

Remove the unnecessary version guards and unconditionally sets
.owner = THIS_MODULE in the affected example code.

Ref: sysprog21#348

Signed-off-by: @visitorckw

Author: EricccTaiwan

main.c

@@ -453,9 +453,7 @@ static int kxo_release(struct inode *inode, struct file *filp)
 }
 
 static const struct file_operations kxo_fops = {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 4, 0)
     .owner = THIS_MODULE,
-#endif
     .read = kxo_read,
 #if LINUX_VERSION_CODE < KERNEL_VERSION(6, 12, 0)
     .llseek = no_llseek,