[Gradle, K/N] Fix broken iOS, watchOS, tvOS tests

They were broken in 2a8e2613a2

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/native/CommonNativeIT.kt

@@ -35,7 +35,7 @@ class CommonNativeIT : BaseGradleIT() {
             assertTasksExecuted(libCompileTasks)
             libTargets.forEach {
                 assertContains("Configuring $it")
-                assertFileExists("lib/build/classes/kotlin/$it/main/lib.klib")
+                assertFileExists("lib/build/classes/kotlin/$it/main/klib/lib.klib")
             }
         }
 
@@ -46,7 +46,7 @@ class CommonNativeIT : BaseGradleIT() {
             assertTasksExecuted(appLinkTestTasks)
 
             appTargets.forEach {
-                assertFileExists("app/build/classes/kotlin/$it/main/app.klib")
+                assertFileExists("app/build/classes/kotlin/$it/main/klib/app.klib")
                 assertFileExists("app/build/bin/$it/debugFramework")
                 assertFileExists("app/build/bin/$it/debugTest")
             }