Source have_innodb_plugin.inc in the plugin tests.

mysql-test/suite/innodb_plugin/t/innodb_bug53592.test

@@ -2,7 +2,7 @@
 # table after fast alter table added unique key". The fix is to make
 # sure index number lookup should go through "index translation table".
 
---source include/have_innodb.inc
+--source include/have_innodb_plugin.inc
 
 # Use FIC for index creation
 set old_alter_table=0;

mysql-test/suite/innodb_plugin/t/innodb_multi_update.test

--- source include/have_innodb.inc
+-- source include/have_innodb_plugin.inc
 
 #
 # Test multi update with different join methods