"Unused receiver parameter" inspection: Fix false negative in same class (KT-23897)

#KT-23897 Fixed

idea/testData/inspectionsLocal/unusedReceiverParameter/functionInSameClass.kt

@@ -0,0 +1,21 @@
+// WITH_RUNTIME
+
+class Test(val str: String) {
+
+    private fun <caret>Test.print() {
+        println(str)
+        println(this.str)
+        println(this@print.str)
+        println()
+    }
+
+    fun test(test: Test) {
+        print()
+        test.print()
+        Test("three").print()
+    }
+}
+
+fun main(args: Array<String>) {
+    Test("one").test(Test("two"))
+}