Set correct TBB library name in debug build and remove warning related to...

Set correct TBB library name in debug build and remove warning related to rpath dependency from symlink.
test=develop

cmake/external/ngraph.cmake

@@ -44,7 +44,11 @@ SET(NGRAPH_INC_DIR         ${NGRAPH_INSTALL_DIR}/include)
 SET(NGRAPH_LIB_DIR         ${NGRAPH_INSTALL_DIR}/${CMAKE_INSTALL_LIBDIR})
 SET(NGRAPH_SHARED_LIB_NAME libngraph.so)
 SET(NGRAPH_CPU_LIB_NAME    libcpu_backend.so)
-SET(NGRAPH_TBB_LIB_NAME    libtbb.so.2)
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    SET(NGRAPH_TBB_LIB_NAME    libtbb_debug.so.2)
+else()
+    SET(NGRAPH_TBB_LIB_NAME    libtbb.so.2)
+endif()
 SET(NGRAPH_GIT_REPO        "https://github.com/NervanaSystems/ngraph.git")
 SET(NGRAPH_SHARED_LIB      ${NGRAPH_LIB_DIR}/${NGRAPH_SHARED_LIB_NAME})
 SET(NGRAPH_CPU_LIB         ${NGRAPH_LIB_DIR}/${NGRAPH_CPU_LIB_NAME})
@@ -66,16 +70,7 @@ ExternalProject_Add(
     CMAKE_ARGS          -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
     CMAKE_ARGS          -DMKLDNN_INCLUDE_DIR=${MKLDNN_INC_DIR}
     CMAKE_ARGS          -DMKLDNN_LIB_DIR=${MKLDNN_INSTALL_DIR}/lib
-)
-
-# Workaround for nGraph expecting mklml to be in mkldnn install directory.
-ExternalProject_Add_Step(
-    ${NGRAPH_PROJECT}
-    PrepareMKL
-    COMMAND ${CMAKE_COMMAND} -E create_symlink ${MKLML_LIB} ${MKLDNN_INSTALL_DIR}/lib/libmklml_intel.so
-    COMMAND ${CMAKE_COMMAND} -E create_symlink ${MKLML_IOMP_LIB} ${MKLDNN_INSTALL_DIR}/lib/libiomp5.so
-    DEPENDEES download
-    DEPENDERS configure
+    CMAKE_ARGS          -DMKLML_LIB_DIR=${MKLML_INSTALL_DIR}/lib
 )
 
 add_dependencies(ngraph ${NGRAPH_PROJECT})