[SCSI] aacraid: use lower snprintf() limit

This is just a cleanup, to silence static checker warnings.  It
doesn't change how the code works.

buf[] can either be BUF_SIZE if this is called from sysfs, or it can
be 16 if it's called from aac_get_adapter_info() via
aac_get_serial_number().  We use the smaller limit here.

sizeof(dev->supplement_adapter_info.MfgPcbaSerialNo) is 12 so there
is actually no chance of hitting either limit.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: Achim Leubner <Achim_Leubner@pmc-sierra.com> 
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

drivers/scsi/aacraid/linit.c

@@ -894,16 +894,17 @@ static ssize_t aac_show_serial_number(struct device *device,
 	int len = 0;
 
 	if (le32_to_cpu(dev->adapter_info.serial[0]) != 0xBAD0)
-		len = snprintf(buf, PAGE_SIZE, "%06X\n",
+		len = snprintf(buf, 16, "%06X\n",
 		  le32_to_cpu(dev->adapter_info.serial[0]));
 	if (len &&
 	  !memcmp(&dev->supplement_adapter_info.MfgPcbaSerialNo[
 	    sizeof(dev->supplement_adapter_info.MfgPcbaSerialNo)-len],
 	  buf, len-1))
-		len = snprintf(buf, PAGE_SIZE, "%.*s\n",
+		len = snprintf(buf, 16, "%.*s\n",
 		  (int)sizeof(dev->supplement_adapter_info.MfgPcbaSerialNo),
 		  dev->supplement_adapter_info.MfgPcbaSerialNo);
-	return len;
+
+	return min(len, 16);
 }
 
 static ssize_t aac_show_max_channel(struct device *device,