irqchip/irq-mvebu-gicp: Allocate enough memory for spi_bitmap

BITS_TO_LONGS() gives us the number of longs we need, but we want to
allocate the number of bytes.

Fixes: a68a63cb4d ("irqchip/irq-mvebu-gicp: Add new driver for Marvell GICP")
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/irq-mvebu-gicp.c

@@ -226,8 +226,8 @@ static int mvebu_gicp_probe(struct platform_device *pdev)
 	}
 
 	gicp->spi_bitmap = devm_kzalloc(&pdev->dev,
-					BITS_TO_LONGS(gicp->spi_cnt),
-					GFP_KERNEL);
+				BITS_TO_LONGS(gicp->spi_cnt) * sizeof(long),
+				GFP_KERNEL);
 	if (!gicp->spi_bitmap)
 		return -ENOMEM;