usb: misc: add missing continue in switch

commit 2c930e3d0aed1505e86e0928d323df5027817740 upstream.

Add missing continue in switch.

Addresses-Coverity-ID: 1248733
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>