HID: sony: Use __u8 * for the buffer in sixaxis_set_operational_usb()

Use the same type declared in the prototypes of functions that are going
to accept the buffer as parameter.
Signed-off-by: NAntonio Ospite <ao2@ao2.it>
Acked-by: NFrank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/hid/hid-sony.c

@@ -1134,7 +1134,7 @@ static int sixaxis_set_operational_usb(struct hid_device *hdev)
 	int ret;
 	const int buf_size =
 		max(SIXAXIS_REPORT_0xF2_SIZE, SIXAXIS_REPORT_0xF5_SIZE);
-	char *buf = kmalloc(buf_size, GFP_KERNEL);
+	__u8 *buf = kmalloc(buf_size, GFP_KERNEL);
 
 	if (!buf)
 		return -ENOMEM;