USB: adding comment for ipaq forcing number of ports

The reason for forcing a number of ports should be documented.

Signed-off-by: Oliver Neukum <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/serial/ipaq.c

···
 	.description =		"PocketPC PDA",
 	.usb_driver = 		&ipaq_driver,
 	.id_table =		ipaq_id_table,
+	/*
+	 * some devices have an extra endpoint, which
+	 * must be ignored as it would make the core
+	 * create a second port which oopses when used
+	 */
 	.num_ports =		1,
 	.open =			ipaq_open,
 	.close =		ipaq_close,