fix stdin input

rabit-learn/io/hdfs-inl.h

@@ -78,7 +78,7 @@ class HDFSStream : public utils::ISeekStream {
   }
   inline void Close(void) {
     if (fp_ != NULL) {
-      if (hdfsCloseFile(fs_, fp_) == 0) {
+      if (hdfsCloseFile(fs_, fp_) == -1) {
         int errsv = errno;
         utils::Error("HDFSStream.Close Error:%s", strerror(errsv));
       }

rabit-learn/io/line_split-inl.h

@@ -140,8 +140,10 @@ class LineSplitBase : public InputSplit {
 class SingleFileSplit : public InputSplit {
  public:
   explicit SingleFileSplit(const char *fname) {
-    if (!strcmp(fname, "stdin")) {      
-      use_stdin_ = true;
+    if (!strcmp(fname, "stdin")) {
+#ifndef RABIT_STRICT_CXX98_
+      use_stdin_ = true; fp_ = stdin;
+#endif
     }
     if (!use_stdin_) {
       fp_ = utils::FopenCheck(fname, "r");