Don't report "cannot infer visibility" on property accessors

If the diagnostic is already reported on the corresponding property, no need to
report it again for accessors

compiler/testData/diagnostics/tests/override/CannotInferVisibilityForProperty.kt

@@ -0,0 +1,13 @@
+trait T {
+    internal var foo: Long
+}
+
+trait U {
+    protected var foo: Long
+}
+
+trait V : T, U {
+    <!CANNOT_INFER_VISIBILITY!>override var foo: Long<!>
+}
+
+trait <!CANNOT_INFER_VISIBILITY!>W<!> : T, U