prevent calling request_irq() with a known invalid IRQ number and
preserve the return value of the platform_get_irq() function
Signed-off-by: NLothar Waßmann <LW@KARO-electronics.de>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>