posix-clock: Remove duplicate compat ioctl() handler

The normal and compat ioctl handlers are identical,
which is fine as compat ioctls are detected and handled dynamically
inside the underlying clock implementation.
The duplicate definition however is unnecessary.

Just reuse the regular ioctl handler also for compat ioctls.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Link: https://lore.kernel.org/all/20250225-posix-clock-compat-cleanup-v2-1-30de86457a2b@weissschuh.net

Author: t-8ch

kernel/time/posix-clock.c

@@ -90,26 +90,6 @@ static long posix_clock_ioctl(struct file *fp,
 	return err;
 }
 
-#ifdef CONFIG_COMPAT
-static long posix_clock_compat_ioctl(struct file *fp,
-				     unsigned int cmd, unsigned long arg)
-{
-	struct posix_clock_context *pccontext = fp->private_data;
-	struct posix_clock *clk = get_posix_clock(fp);
-	int err = -ENOTTY;
-
-	if (!clk)
-		return -ENODEV;
-
-	if (clk->ops.ioctl)
-		err = clk->ops.ioctl(pccontext, cmd, arg);
-
-	put_posix_clock(clk);
-
-	return err;
-}
-#endif
-
 static int posix_clock_open(struct inode *inode, struct file *fp)
 {
 	int err;
@@ -171,11 +151,9 @@ static const struct file_operations posix_clock_file_operations = {
 	.read		= posix_clock_read,
 	.poll		= posix_clock_poll,
 	.unlocked_ioctl	= posix_clock_ioctl,
+	.compat_ioctl	= posix_clock_ioctl,
 	.open		= posix_clock_open,
 	.release	= posix_clock_release,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl	= posix_clock_compat_ioctl,
-#endif
 };
 
 int posix_clock_register(struct posix_clock *clk, struct device *dev)