USB: CDC: fix sanity checks in CDC union parser

A few checks checked for the size of the pointer to a structure
instead of the structure itself. Copy & paste issue presumably.

Fixes: e4c6fb77 ("usbnet: move the CDC parser into USB core")
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot+45a53506b65321c1fe91@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20190813093541.18889-1-oneukum@suse.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/message.c

@@ -2218,14 +2218,14 @@ int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
 				(struct usb_cdc_dmm_desc *)buffer;
 			break;
 		case USB_CDC_MDLM_TYPE:
-			if (elength < sizeof(struct usb_cdc_mdlm_desc *))
+			if (elength < sizeof(struct usb_cdc_mdlm_desc))
 				goto next_desc;
 			if (desc)
 				return -EINVAL;
 			desc = (struct usb_cdc_mdlm_desc *)buffer;
 			break;
 		case USB_CDC_MDLM_DETAIL_TYPE:
-			if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *))
+			if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
 				goto next_desc;
 			if (detail)
 				return -EINVAL;