migration: Don't return for postcopy_send_discard_bm_ram()

postcopy_send_discard_bm_ram() always return zero. Since it can't
fail, simplify and do not return anything.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Author: philmd

migration/ram.c

@@ -2419,14 +2419,12 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
 /**
  * postcopy_send_discard_bm_ram: discard a RAMBlock
  *
- * Returns zero on success
- *
  * Callback from postcopy_each_ram_send_discard for each RAMBlock
  *
  * @ms: current migration state
  * @block: RAMBlock to discard
  */
-static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block)
+static void postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block)
 {
     unsigned long end = block->used_length >> TARGET_PAGE_BITS;
     unsigned long current;
@@ -2450,8 +2448,6 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block)
         postcopy_discard_send_range(ms, one, discard_length);
         current = one + discard_length;
     }
-
-    return 0;
 }
 
 static void postcopy_chunk_hostpages_pass(MigrationState *ms, RAMBlock *block);