irqchip: irq-crossbar: Not allocating enough memory

We are allocating the size of a pointer and not the size of the data.
This will lead to memory corruption.

There isn't actually a "cb_device" struct, btw.  The code is only able
to compile because GCC knows that all pointers are the same size.

Fixes: 96ca848ef7ea ('DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP')

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Sricharan R <r.sricharan@ti.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/20140403072134.GA14286@mwanda
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index fc817d2..3d15d16 100644
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -107,7 +107,7 @@
 	int i, size, max, reserved = 0, entry;
 	const __be32 *irqsr;
 
-	cb = kzalloc(sizeof(struct cb_device *), GFP_KERNEL);
+	cb = kzalloc(sizeof(*cb), GFP_KERNEL);
 
 	if (!cb)
 		return -ENOMEM;