usb: gadget: storage-common: Fix old comment about qualifier descriptor

Device qualifier descriptor is now generated by composite.c
code. So let's fix this old comment by removing parts which
are no longer valid.
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Krzysztof Opasiak <kopasiak90@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/storage_common.c

@@ -83,9 +83,7 @@ EXPORT_SYMBOL_GPL(fsg_fs_function);
  * USB 2.0 devices need to expose both high speed and full speed
  * descriptors, unless they only run at full speed.
  *
- * That means alternate endpoint descriptors (bigger packets)
- * and a "device qualifier" ... plus more construction options
- * for the configuration descriptor.
+ * That means alternate endpoint descriptors (bigger packets).
  */
 struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
 	.bLength =		USB_DT_ENDPOINT_SIZE,