clean up ShuffledJoin.createVars and fix unit text

Author: c21

sql/core/src/main/scala/org/apache/spark/sql/execution/joins/ShuffledJoin.scala

@@ -68,17 +68,17 @@ trait ShuffledJoin extends BaseJoinExec {
              |$isNull = $row.isNullAt($i);
              |$value = $isNull ? $defaultValue : ($valueCode);
            """.stripMargin
-        val leftVarsDecl =
+        val varDecl =
           s"""
              |boolean $isNull = false;
              |$javaType $value = $defaultValue;
            """.stripMargin
         (ExprCode(code, JavaCode.isNullVariable(isNull), JavaCode.variable(value, a.dataType)),
-          leftVarsDecl)
+          varDecl)
       } else {
         val code = code"$value = $valueCode;"
-        val leftVarsDecl = s"""$javaType $value = $defaultValue;"""
-        (ExprCode(code, FalseLiteral, JavaCode.variable(value, a.dataType)), leftVarsDecl)
+        val varDecl = s"""$javaType $value = $defaultValue;"""
+        (ExprCode(code, FalseLiteral, JavaCode.variable(value, a.dataType)), varDecl)
       }
     }.unzip
   }

sql/core/src/test/scala/org/apache/spark/sql/execution/metric/SQLMetricsSuite.scala

@@ -346,8 +346,8 @@ class SQLMetricsSuite extends SharedSparkSession with SQLMetricsTestUtils
     val rightDf = (1 to 10).map(i => (i, i.toString)).toSeq.toDF("key2", "value")
     Seq((0L, "right_outer", leftDf, rightDf, 10L, false),
       (0L, "left_outer", rightDf, leftDf, 10L, false),
-      (0L, "right_outer", leftDf, rightDf, 10L, true),
-      (0L, "left_outer", rightDf, leftDf, 10L, true),
+      (1L, "right_outer", leftDf, rightDf, 10L, true),
+      (1L, "left_outer", rightDf, leftDf, 10L, true),
       (2L, "left_anti", rightDf, leftDf, 8L, true),
       (2L, "left_semi", rightDf, leftDf, 2L, true),
       (1L, "left_anti", rightDf, leftDf, 8L, false),