migration: Use qemu_file_transferred_noflush() for block migration.

We only care about the amount of bytes transferred.  Flushing is done
by the system somewhere else.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20230530183941.7223-4-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

migration/block.c

@@ -755,7 +755,7 @@ static int block_save_setup(QEMUFile *f, void *opaque)
 static int block_save_iterate(QEMUFile *f, void *opaque)
 {
     int ret;
-    uint64_t last_bytes = qemu_file_transferred(f);
+    uint64_t last_bytes = qemu_file_transferred_noflush(f);
 
     trace_migration_block_save("iterate", block_mig_state.submitted,
                                block_mig_state.transferred);
@@ -807,7 +807,7 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
     }
 
     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
-    uint64_t delta_bytes = qemu_file_transferred(f) - last_bytes;
+    uint64_t delta_bytes = qemu_file_transferred_noflush(f) - last_bytes;
     return (delta_bytes > 0);
 }