Explicit this inspection: fix false negative with local variable

#KT-30136 Fixed

idea/testData/inspectionsLocal/explicitThis/functionWithSameNameInvocableVariable.kt

@@ -0,0 +1,14 @@
+// PROBLEM: none
+class Some {
+    operator fun invoke() {}
+}
+
+class Other {
+    fun foo() {
+        val a = Some()
+        <caret>this.a()
+        a()
+    }
+
+    fun a() {}
+}