HDFS-14950. fix missing libhdfspp lib in dist-package (#1947)

libhdfspp.{a,so} are missed in dist-package.
This patch fixed this by copying these libs to the right directory

Signed-off-by: Yuan Zhou <yuan.zhou@intel.com>
(cherry picked from commit e756fe3590906bfd8ffe4ab5cc8b9b24a9b2b4b2)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/CMakeLists.txt

@@ -263,6 +263,7 @@ if (HADOOP_BUILD)
     ${CMAKE_THREAD_LIBS_INIT}
   )
   set_target_properties(hdfspp PROPERTIES SOVERSION ${LIBHDFSPP_VERSION})
+  hadoop_dual_output_directory(hdfspp ${OUT_DIR})
 else (HADOOP_BUILD)
   add_library(hdfspp_static STATIC ${EMPTY_FILE_CC} ${LIBHDFSPP_ALL_OBJECTS})
   target_link_libraries(hdfspp_static