[JVM_IR] Fix check for inline class property backing in lowering.

The inline class lowering would attempt to lower a companion object
property backing field.

^KT-47762 Fixed.

compiler/testData/codegen/box/inlineClasses/kt47762.kt

@@ -0,0 +1,11 @@
+inline class A(val a: Int = 1) {
+    companion object {
+        val a: Int = 2
+    }
+}
+
+fun box(): String {
+    if (A.a != 2) return "FAIL1"
+    val instance = A()
+    return if (instance.a != 1) "FAIL2" else "OK"
+}