irqchip: brcmstb-l2: Fix error handling of irq_of_parse_and_map
irqchip: brcmstb-l2: Fix error handling of irq_of_parse_and_map

Return value of irq_of_parse_and_map() is unsigned int, with 0
indicating failure, so testing for negative result never works.

Signed-off-by: Dmitry Torokhov <10a8c465cefc9bdd6c925e26964d23c90f1141cc@chromium.org>
Acked-by: Florian Fainelli <59190c1867e3222b932a0de3c668eb2d980d69a2@gmail.com>
Tested-by: Kevin Cernekee <3105dbb3dd63fbb4f6371cfb04adc6726f76c56b@gmail.com> 
Link: 11dc83b090715c0b9612240a124553ab79f9d50b@dtor-ws
Signed-off-by: Jason Cooper <68c46a606457643eab92053c1c05574abb26f861@lakedaemon.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs