[FIR] Add correctly reported diagnostics to testdata

compiler/fir/analysis-tests/testData/resolveWithStdlib/contracts/fromSource/good/returnsImplies/propertyAccessors.kt

@@ -14,7 +14,7 @@ var Any?.isNotNull: Boolean
     set(value) {
         contract {
             returns() implies (this@isNotNull != null)
-            require(this != null)
+            <!ERROR_IN_CONTRACT_DESCRIPTION!>require(this != null)<!>
         }
     }
 
@@ -27,4 +27,4 @@ fun test_1(a: A?) {
 fun test_2(a: A?) {
     a.isNotNull = true
     a.foo()
-}
+}