[POWERPC] Use ARRAY_SIZE macro when appropriate

Use ARRAY_SIZE macro already defined in linux/kernel.h

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c
index 4bbda6b..6c5c5dd 100644
--- a/arch/powerpc/lib/rheap.c
+++ b/arch/powerpc/lib/rheap.c
@@ -14,6 +14,7 @@
  */
 #include <linux/types.h>
 #include <linux/errno.h>
+#include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 
@@ -671,7 +672,7 @@
 	int maxnr;
 	int i, nr;
 
-	maxnr = sizeof(st) / sizeof(st[0]);
+	maxnr = ARRAY_SIZE(st);
 
 	printk(KERN_INFO
 	       "info @0x%p (%d slots empty / %d max)\n",