slashes fix for windows

Author: shssf

dpnp/backend/CMakeLists.txt

@@ -42,7 +42,7 @@ else()
   if(UNIX)
     set(DPNP_ONEAPI_ROOT "/opt/intel/oneapi" CACHE PATH "Folder contains oneapi tool set")
   elseif(WIN32)
-    set(DPNP_ONEAPI_ROOT "C:\Program Files (x86)\Intel\oneAPI" CACHE PATH "Folder contains oneapi tool set")
+    set(DPNP_ONEAPI_ROOT "C:/Program Files (x86)/Intel/oneAPI" CACHE PATH "Folder contains oneapi tool set")
   else()
     message(FATAL_ERROR "Unsupported system ${CMAKE_SYSTEM}")
   endif()