USB: cdnsp: drop irq-flags initialisations

There's no need to initialise irq-flags variables before saving the
interrupt state.

Cc: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210519093303.10789-2-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>