moved unknown sys variable test into VariableErrorsTests

Author: angelamayxie

enginetest/queries/variable_queries.go

@@ -22,12 +22,6 @@ import (
 )
 
 var VariableQueries = []ScriptTest{
-	{
-		Name:        "use string name for foreign_key checks",
-		SetUpScript: []string{},
-		Query:       "select @@GLOBAL.unknown",
-		ExpectedErr: sql.ErrUnknownSystemVariable,
-	},
 	{
 		Name:        "use string name for foreign_key checks",
 		SetUpScript: []string{},
@@ -649,6 +643,10 @@ var VariableQueries = []ScriptTest{
 }
 
 var VariableErrorTests = []QueryErrorTest{
+	{
+		Query:       "select @@GLOBAL.unknown",
+		ExpectedErr: sql.ErrUnknownSystemVariable,
+	},
 	{
 		Query:       "set @@does_not_exist = 100",
 		ExpectedErr: sql.ErrUnknownSystemVariable,