USB: Support for BT On-Air USB modem in cdc-acm.c

The patch below is a necessary workaround to support the BT On-Air USB modem, which
fails to initialise properly during normal probing thus:

Sep 30 17:34:57 sled kernel: drivers/usb/class/cdc-acm.c: Zero length descriptor references
Sep 30 17:34:57 sled kernel: cdc_acm: probe of 1-1.2:1.0 failed with error -22

Adding the patch below causes the probing section to be skipped, and the modem
then initialises correctly.

Signed-off-by: Chris Malley <mail@chrismalley.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/class/cdc-acm.c

@@ -1083,6 +1083,9 @@ static struct usb_device_id acm_ids[] = {
 	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
 	},
+	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
+	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
+	},
 	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
 	.driver_info = SINGLE_RX_URB, /* firmware bug */
 	},