Replace lateinit with null in binding variants

kotlin-result-coroutines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/binding/SuspendableBinding.kt

@@ -36,7 +36,7 @@ public suspend inline fun <V, E> binding(crossinline block: suspend SuspendableR
             }
         }
     } catch (ex: BindCancellationException) {
-        receiver.result
+        receiver.result!!
     }
 }
 
@@ -52,13 +52,13 @@ internal class SuspendableResultBindingImpl<E>(
 ) : SuspendableResultBinding<E>, CoroutineScope by delegate {
 
     private val mutex = Mutex()
-    lateinit var result: Err<E>
+    var result: Result<Nothing, E>? = null
 
     override suspend fun <V> Result<V, E>.bind(): V {
         return when (this) {
             is Ok -> value
             is Err -> mutex.withLock {
-                if (::result.isInitialized.not()) {
+                if (result == null) {
                     result = this
                     coroutineContext.cancel(BindCancellationException)
                 }

kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/Binding.kt

@@ -27,12 +27,12 @@ public inline fun <V, E> binding(crossinline block: ResultBinding<E>.() -> V): R
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
 
-    val receiver = ResultBindingImpl<E>()
-
-    return try {
-        with(receiver) { Ok(block()) }
-    } catch (ex: BindException) {
-        receiver.result
+    return with(ResultBindingImpl<E>()) {
+        try {
+            Ok(block())
+        } catch (ex: BindException) {
+            result!!
+        }
     }
 }
 
@@ -45,7 +45,7 @@ public interface ResultBinding<E> {
 @PublishedApi
 internal class ResultBindingImpl<E> : ResultBinding<E> {
 
-    lateinit var result: Err<E>
+    var result: Result<Nothing, E>? = null
 
     override fun <V> Result<V, E>.bind(): V {
         return when (this) {

kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/SuspendableBinding.kt

@@ -22,11 +22,11 @@ public suspend inline fun <V, E> binding(crossinline block: suspend ResultBindin
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
 
-    val receiver = ResultBindingImpl<E>()
-
-    return try {
-        with(receiver) { Ok(block()) }
-    } catch (ex: BindException) {
-        receiver.result
+    return with(ResultBindingImpl<E>()) {
+        try {
+            Ok(block())
+        } catch (ex: BindException) {
+            result!!
+        }
     }
 }