add context argument to read_raw_free()

- will allow backends to take into account runtime parameters or other
  state in memory allocation/deallocation

src/bake-backend.h

@@ -32,7 +32,7 @@ typedef int (*bake_write_bulk_fn)(backend_context_t context,
                                   hg_addr_t         source,
                                   size_t            bulk_offset);
 
-typedef void (*free_fn)(void*);
+typedef void (*free_fn)(backend_context_t context, void*);
 
 typedef int (*bake_read_raw_fn)(backend_context_t context,
                                 bake_region_id_t  rid,

src/bake-file-backend.c

@@ -431,7 +431,7 @@ static int bake_file_write_bulk(backend_context_t context,
  * bake_file_read_raw().  It is like a normal fre() except that it must
  * round down to block alignment to find the correct pointer to free.
  */
-static void bake_file_read_raw_free(void* ptr)
+static void bake_file_read_raw_free(backend_context_t context, void* ptr)
 {
     free((void*)(BAKE_ALIGN_DOWN(ptr)));
     return;

src/bake-server.c

@@ -778,7 +778,7 @@ static void bake_eager_read_ult(hg_handle_t handle)
 finish:
     UNLOCK_PROVIDER;
     RESPOND_AND_CLEANUP;
-    if (free_data) free_data(out.buffer);
+    if (free_data) free_data(target->context, out.buffer);
 }
 DEFINE_MARGO_RPC_HANDLER(bake_eager_read_ult)