IB/core: Use ARRAY_SIZE macro for mandatory_table

Use ARRAY_SIZE() macro already defined in kernel.h instead of open
coding equivalent code.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/device.c

@@ -36,6 +36,7 @@
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/errno.h>
+#include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
@@ -93,7 +94,7 @@ static int ib_device_check_mandatory(struct ib_device *device)
 	};
 	int i;
 
-	for (i = 0; i < sizeof mandatory_table / sizeof mandatory_table[0]; ++i) {
+	for (i = 0; i < ARRAY_SIZE(mandatory_table); ++i) {
 		if (!*(void **) ((void *) device + mandatory_table[i].offset)) {
 			printk(KERN_WARNING "Device %s is missing mandatory function %s\n",
 			       device->name, mandatory_table[i].name);