[UR][Offload] Fix to make offload adapter compile (#19040)

Author: RossBrunton

unified-runtime/source/adapters/offload/enqueue.cpp

@@ -109,7 +109,8 @@ UR_APIEXPORT ur_result_t UR_APICALL urEnqueueMemBufferRead(
 
   ol_event_handle_t EventOut = nullptr;
 
-  void *DevPtr = std::get<BufferMem>(hBuffer->Mem).Ptr;
+  char *DevPtr =
+      reinterpret_cast<char *>(std::get<BufferMem>(hBuffer->Mem).Ptr);
 
   olMemcpy(hQueue->OffloadQueue, pDst, Adapter.HostDevice, DevPtr + offset,
            hQueue->OffloadDevice, size, phEvent ? &EventOut : nullptr);
@@ -139,7 +140,8 @@ UR_APIEXPORT ur_result_t UR_APICALL urEnqueueMemBufferWrite(
 
   ol_event_handle_t EventOut = nullptr;
 
-  void *DevPtr = std::get<BufferMem>(hBuffer->Mem).Ptr;
+  char *DevPtr =
+      reinterpret_cast<char *>(std::get<BufferMem>(hBuffer->Mem).Ptr);
 
   auto Res =
       olMemcpy(hQueue->OffloadQueue, DevPtr + offset, hQueue->OffloadDevice,