[ci] fixed cpplint warnings about braces (#2869)

* [ci] fixed cpplint warnings about braces

* removed excess line

include/LightGBM/tree.h

@@ -134,7 +134,6 @@ class Tree {
   inline int PredictLeafIndex(const double* feature_values) const;
   inline int PredictLeafIndexByMap(const std::unordered_map<int, double>& feature_values) const;
 
-
   inline void PredictContrib(const double* feature_values, int num_features, double* output);
 
   /*! \brief Get Number of leaves*/
@@ -151,7 +150,6 @@ class Tree {
   /*! \brief Get the number of data points that fall at or below this node*/
   inline int data_count(int node) const { return node >= 0 ? internal_count_[node] : leaf_count_[~node]; }
 
-  
   /*!
   * \brief Shrinkage for the tree's output
   *        shrinkage rate (a.k.a learning rate) is used to tune the training process

src/io/file_io.cpp

@@ -170,11 +170,9 @@ std::unique_ptr<VirtualFileReader> VirtualFileReader::Make(
   if (0 == filename.find(kHdfsProto)) {
     WITH_HDFS(return std::unique_ptr<VirtualFileReader>(
         new HDFSFile(filename, O_RDONLY)));
-  } else
-#endif
-  {
-    return std::unique_ptr<VirtualFileReader>(new LocalFile(filename, "rb"));
   }
+#endif
+  return std::unique_ptr<VirtualFileReader>(new LocalFile(filename, "rb"));
 }
 
 std::unique_ptr<VirtualFileWriter> VirtualFileWriter::Make(
@@ -183,23 +181,19 @@ std::unique_ptr<VirtualFileWriter> VirtualFileWriter::Make(
   if (0 == filename.find(kHdfsProto)) {
     WITH_HDFS(return std::unique_ptr<VirtualFileWriter>(
         new HDFSFile(filename, O_WRONLY)));
-  } else
-#endif
-  {
-    return std::unique_ptr<VirtualFileWriter>(new LocalFile(filename, "wb"));
   }
+#endif
+  return std::unique_ptr<VirtualFileWriter>(new LocalFile(filename, "wb"));
 }
 
 bool VirtualFileWriter::Exists(const std::string& filename) {
 #ifdef USE_HDFS
   if (0 == filename.find(kHdfsProto)) {
     WITH_HDFS(HDFSFile file(filename, O_RDONLY); return file.Exists());
-  } else
-#endif
-  {
-    LocalFile file(filename, "rb");
-    return file.Exists();
   }
+#endif
+  LocalFile file(filename, "rb");
+  return file.Exists();
 }
 
 }  // namespace LightGBM