remove get_buffer()

Signed-off-by: Dan Hoeflinger <dan.hoeflinger@intel.com>

Author: danhoeflinger

clang/runtime/dpct-rt/include/dpct/dpl_extras/memory.h

@@ -638,8 +638,6 @@ template <typename T> class device_iterator : public device_pointer<T> {
 
   std::size_t get_idx() const { return idx; } // required
 
-  device_iterator &get_buffer() { return *this; } // required
-
 };
 #endif