xhci: xhci-mem: off by one in xhci_stream_id_to_ring()

BugLink: https://bugs.launchpad.net/bugs/1790620

commit 313db3d6 upstream.

The > should be >= here so that we don't read one element beyond the end
of the ep->stream_info->stream_rings[] array.

Fixes: e9df17eb ("USB: xhci: Correct assumptions about number of rings per endpoint.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/usb/host/xhci-mem.c

@@ -638,7 +638,7 @@ struct xhci_ring *xhci_stream_id_to_ring(
 	if (!ep->stream_info)
 		return NULL;
 
-	if (stream_id > ep->stream_info->num_streams)
+	if (stream_id >= ep->stream_info->num_streams)
 		return NULL;
 	return ep->stream_info->stream_rings[stream_id];
 }