drbd: Do not allow a fencing-policy of resource-and-stonith with protocol A

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 7be069f..0b2bfb5 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -145,6 +145,7 @@
 	ERR_CONNECTED		= 151, /* DRBD 8.3 only */
 	ERR_PERM		= 152,
 	ERR_NEED_APV_93		= 153,
+	ERR_STONITH_AND_PROT_A  = 154,
 
 	/* insert new ones above this line */
 	AFTER_LAST_ERR_CODE