USB: fix location of statement label in dummy-hcd

This patch (as984) fixes a rather elementary mistake in dummy_hcd.
The new statement label should come before the spin_unlock_irqrestore,
not after it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>