acpi: fix printk format warning

Fix printk format warning:

linux-next-20080617/drivers/acpi/processor_throttling.c:1258: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

drivers/acpi/processor_throttling.c

@@ -1255,7 +1255,7 @@ static ssize_t acpi_processor_write_throttling(struct file *file,
 	if (state_val >= pr->throttling.state_count)
 		return -EINVAL;
 
-	snprintf(tmpbuf, 5, "%d", state_val);
+	snprintf(tmpbuf, 5, "%zu", state_val);
 
 	if (strcmp(tmpbuf, charp) != 0)
 		return -EINVAL;