Fix "cannot override invisible member" diagnostic message

Fix "cannot has", delete "in class ..." as it's already present in the message
(function ... defined in class ...)

idea/testData/diagnosticMessage/cannotOverrideInvisibleMember.kt

@@ -0,0 +1,10 @@
+// !DIAGNOSTICS_NUMBER: 1
+// !DIAGNOSTICS: CANNOT_OVERRIDE_INVISIBLE_MEMBER
+
+open class A {
+    private open fun foo() {}
+}
+
+class B : A() {
+    override fun foo() {}
+}