Fix inheritance from protected members of interfaces

#KT-3029 Fixed

compiler/testData/codegen/box/traits/protectedFunDiamond.kt

@@ -0,0 +1,15 @@
+interface A {
+    protected fun foo(): String
+
+    fun box() = foo()
+}
+
+interface B : A
+
+interface C : A {
+    protected override fun foo() = "OK"
+}
+
+class D : B, C
+
+fun box() = D().box()