Suppressing warning about unused variables for selective build of MKL…

…DNN plugin.

inference-engine/src/mkldnn_plugin/CMakeLists.txt

@@ -161,6 +161,11 @@ ie_add_plugin(NAME ${TARGET_NAME}
 
 set_ie_threading_interface_for(${TARGET_NAME})
 
+if(SELECTIVE_BUILD STREQUAL "ON")
+    # After disabling a block of code, some variables might be unused.
+    target_compile_options(${TARGET_NAME} PRIVATE -Wno-unused-variable)
+endif()
+
 target_link_libraries(${TARGET_NAME} PRIVATE mkldnn inference_engine inference_engine_legacy
                                              inference_engine_transformations inference_engine_lp_transformations openvino::conditional_compilation)
 
@@ -202,6 +207,11 @@ target_include_directories(${TARGET_NAME}_obj PRIVATE $<TARGET_PROPERTY:inferenc
 
 set_ie_threading_interface_for(${TARGET_NAME}_obj)
 
+if(SELECTIVE_BUILD STREQUAL "ON")
+    # After disabling a block of code, some variables might be unused.
+    target_compile_options(${TARGET_NAME}_obj PRIVATE -Wno-unused-variable)
+endif()
+
 target_compile_definitions(${TARGET_NAME}_obj
         PRIVATE USE_STATIC_IE IMPLEMENT_INFERENCE_ENGINE_PLUGIN
 )