usb: core: remove local_irq_save() around ->complete() handler

The core disabled interrupts before invocation the ->complete handler
because the handler might have expected that interrupts are disabled.

All handlers were audited and use proper locking now. With it, the core
code no longer needs to disable interrupts before invoking the
->complete handler.
Remove local_irq_save() statement before invoking the ->complete
handler.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>