[media] rc/ir-lirc-codec: cleanup __user tags

The code here treated user pointers correctly, but the __user tags
weren't used correctly so it caused Sparse warnings:
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/ir-lirc-codec.c

@@ -98,7 +98,7 @@ static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
 	return 0;
 }
 
-static ssize_t ir_lirc_transmit_ir(struct file *file, const char *buf,
+static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 				   size_t n, loff_t *ppos)
 {
 	struct lirc_codec *lirc;
@@ -140,10 +140,11 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char *buf,
 }
 
 static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
-			unsigned long __user arg)
+			unsigned long arg)
 {
 	struct lirc_codec *lirc;
 	struct rc_dev *dev;
+	u32 __user *argp = (u32 __user *)(arg);
 	int ret = 0;
 	__u32 val = 0, tmp;
 
@@ -156,7 +157,7 @@ static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 		return -EFAULT;
 
 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
-		ret = get_user(val, (__u32 *)arg);
+		ret = get_user(val, argp);
 		if (ret)
 			return ret;
 	}
@@ -265,7 +266,7 @@ static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 	}
 
 	if (_IOC_DIR(cmd) & _IOC_READ)
-		ret = put_user(val, (__u32 *)arg);
+		ret = put_user(val, argp);
 
 	return ret;
 }