MIPS: OCTEON: irq: Check for null return on kzalloc allocation

The allocation of host_data is not null checked, leading to a null
pointer dereference if the allocation fails. Fix this by adding a null
check and return with -ENOMEM.

Fixes: 64b139f9 ("MIPS: OCTEON: irq: add CIB and other fixes")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "Steven J. Hill" <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/18658/Signed-off-by: James Hogan <jhogan@kernel.org>

arch/mips/cavium-octeon/octeon-irq.c

@@ -2277,6 +2277,8 @@ static int __init octeon_irq_init_cib(struct device_node *ciu_node,
 	}
 
 	host_data = kzalloc(sizeof(*host_data), GFP_KERNEL);
+	if (!host_data)
+		return -ENOMEM;
 	raw_spin_lock_init(&host_data->lock);
 
 	addr = of_get_address(ciu_node, 0, NULL, NULL);