cmake: properly set flags for release-internal

Change-Id: Ic080c67acacb48005238d5db44dc76736a85fca8
Signed-off-by: Artur Harasimiuk <artur.harasimiuk@intel.com>

Author: ArturHarasimiuk

CMakeLists.txt

@@ -37,10 +37,10 @@ if(WIN32)
     add_definitions(-D_CRT_SECURE_NO_WARNINGS -DWDDM_VERSION_NUMBER=23)
 endif()
 
-set(CMAKE_C_FLAGS_RELEASEINTERNAL ${CMAKE_C_FLAGS_RELEASE})
-set(CMAKE_CXX_FLAGS_RELEASEINTERNAL ${CMAKE_CXX_FLAGS_RELEASE})
-set(CMAKE_SHARED_LINKER_FLAGS_RELEASEINTERNAL ${CMAKE_SHARED_LINKER_FLAGS_RELEASE})
-set(CMAKE_EXE_LINKER_FLAGS_RELEASEINTERNAL ${CMAKE_EXE_LINKER_FLAGS_RELEASE})
+set(CMAKE_C_FLAGS_RELEASEINTERNAL "${CMAKE_C_FLAGS_RELEASE}")
+set(CMAKE_CXX_FLAGS_RELEASEINTERNAL "${CMAKE_CXX_FLAGS_RELEASE}")
+set(CMAKE_SHARED_LINKER_FLAGS_RELEASEINTERNAL "${CMAKE_SHARED_LINKER_FLAGS_RELEASE}")
+set(CMAKE_EXE_LINKER_FLAGS_RELEASEINTERNAL "${CMAKE_EXE_LINKER_FLAGS_RELEASE}")
 
 string(TOLOWER "${CMAKE_BUILD_TYPE}" BUILD_TYPE_lower)
 if("${BUILD_TYPE_lower}" STREQUAL "releaseinternal")