mips: sgi-ip22: add a check for the return of kzalloc()

kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check it to
prevent potential wrong memory access.
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/sgi-ip22/ip22-gio.c

@@ -363,6 +363,8 @@ static void ip22_check_gio(int slotno, unsigned long addr, int irq)
 		printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
 		       slotno, name, id);
 		gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
+		if (!gio_dev)
+			return;
 		gio_dev->name = name;
 		gio_dev->slotno = slotno;
 		gio_dev->id.id = id;