HID: roccat: rename roccat_common functions to roccat_common2

Did this to illustrate my understanding of the firmware generations:
Valo and Kone were 1st generation
Arvo was externaly developed and lies in the middle
All others until now are considered 2nd generation

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-roccat-savu.c b/drivers/hid/hid-roccat-savu.c
index 19f9c47..29e87d7 100644
--- a/drivers/hid/hid-roccat-savu.c
+++ b/drivers/hid/hid-roccat-savu.c
@@ -44,7 +44,7 @@
 		return -EINVAL;
 
 	mutex_lock(&savu->savu_lock);
-	retval = roccat_common_receive(usb_dev, command, buf, real_size);
+	retval = roccat_common2_receive(usb_dev, command, buf, real_size);
 	mutex_unlock(&savu->savu_lock);
 
 	return retval ? retval : real_size;
@@ -64,7 +64,7 @@
 		return -EINVAL;
 
 	mutex_lock(&savu->savu_lock);
-	retval = roccat_common_send_with_status(usb_dev, command,
+	retval = roccat_common2_send_with_status(usb_dev, command,
 			(void *)buf, real_size);
 	mutex_unlock(&savu->savu_lock);