staging: wlan-ng: silence incorrect type in argument 1 (different address spaces)

Currently p80211knetdev_do_ioctl use type casting to req->data to prevent
sparse warning while calling memdup_user, instead of type casting it here,
its better to change data type for data inside p80211ioctl_req to include
__user.
Signed-off-by: Ashish Kalra <eashishkalra@gmail.com>
Link: https://lore.kernel.org/r/YI1dKdfBKaSh3J8v@ashish-NUC8i5BEHSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/p80211ioctl.h

@@ -81,7 +81,7 @@
 
 struct p80211ioctl_req {
 	char name[WLAN_DEVNAMELEN_MAX];
-	caddr_t data;
+	char __user *data;
 	u32 magic;
 	u16 len;
 	u32 result;

drivers/staging/wlan-ng/p80211netdev.c

@@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
 		goto bail;
 	}
 
-	msgbuf = memdup_user((void __user *)req->data, req->len);
+	msgbuf = memdup_user(req->data, req->len);
 	if (IS_ERR(msgbuf)) {
 		result = PTR_ERR(msgbuf);
 		goto bail;
@@ -579,7 +579,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
 
 	if (result == 0) {
 		if (copy_to_user
-		    ((void __user *)req->data, msgbuf, req->len)) {
+		    (req->data, msgbuf, req->len)) {
 			result = -EFAULT;
 		}
 	}