usb: wusbcore: convert nested lock to use spin_lock instead of spin_lock_irq

Nesting a spin_lock_irq/unlock_irq inside a lock that has already
disabled interrupts will enable interrupts before we are ready when
spin_unlock_irq is called.  This patch converts the inner lock to use
spin_lock and spin_unlock instead.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>