[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/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -18910,6 +18910,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/inlineClasses/kt47609.kt");
         }
 
+        @Test
+        @TestMetadata("kt47762.kt")
+        public void testKt47762() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/kt47762.kt");
+        }
+
         @Test
         @TestMetadata("mangledDefaultParameterFunction.kt")
         public void testMangledDefaultParameterFunction() throws Exception {