Unnecessary variable: do not suggest in case of name duplication

So #KT-20300 Fixed

idea/testData/inspectionsLocal/unnecessaryVariable/it.kt

@@ -0,0 +1,11 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+fun foo(a: List<String>, b: List<Int>) {
+    a.forEach {
+        val <caret>a2 = it
+        b.forEach {
+            println(a2.length)
+        }
+    }
+}

idea/testData/inspectionsLocal/unnecessaryVariable/parameterWithSameNameBelow.kt

@@ -0,0 +1,15 @@
+// PROBLEM: none
+
+interface Callback {
+    fun on(id: Int)
+}
+
+fun called(id: Int) {
+    val <caret>calledId = id
+    object : Callback {
+        override fun on(id: Int) {
+            if (id == calledId) {
+            }
+        }
+    }
+}