[NaCl SDK] nacl_io: Enable isatty running under sel_ldr.

native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc

Index: native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
index 9c59b6a209394c4ecf48e8452193679b8cfe0dad..8b247c21fd9440b06b499b2954ee5ba5fc40c143 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
@@ -576,16 +576,16 @@ int KernelProxy::isatty(int fd) {
   Error error = AcquireHandle(fd, &handle);
   if (error) {
     errno = error;
-    return -1;
+    return 0;
   }
 
-  error = handle->node()->IsaTTY();
+  error = handle->node()->Isatty();
   if (error) {
     errno = error;
-    return -1;
+    return 0;
   }
 
-  return 0;
+  return 1;
 }
 
 int KernelProxy::ioctl(int fd, int request, va_list args) {