[FIR] Report VAL_REASSIGNMENT on assign to non-local vals

In this commit reporting on member properties in init section of class
  is not supported (see KT-55528)

^KT-55493 Fixed

compiler/testData/diagnostics/tests/controlFlowAnalysis/initializationInLocalClass.fir.kt

@@ -86,5 +86,5 @@ class My {
 <!MUST_BE_INITIALIZED!>val top: Int<!>
 
 fun init() {
-    top = 1
+    <!VAL_REASSIGNMENT!>top<!> = 1
 }