drbd: Rename enum drbd_ret_codes to enum drbd_ret_code

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 41da654..d92f989 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -103,7 +103,7 @@
 };
 
 /* KEEP the order, do not delete or insert. Only append. */
-enum drbd_ret_codes {
+enum drbd_ret_code {
 	ERR_CODE_BASE		= 100,
 	NO_ERROR		= 101,
 	ERR_LOCAL_ADDR		= 102,