block migration: Initialize remaining BlkMigState fields

In case we restart a migration, submitted, read_done, transferred, and
print_completion need to be reinitialized to 0.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

block-migration.c

@@ -248,6 +248,11 @@ static void init_blk_migration(QEMUFile *f)
     BlkMigDevState *bmds;
     BlockDriverState *bs;
 
+    block_mig_state.submitted = 0;
+    block_mig_state.read_done = 0;
+    block_mig_state.transferred = 0;
+    block_mig_state.print_completion = 0;
+
     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
         if (bs->type == BDRV_TYPE_HD) {
             bmds = qemu_mallocz(sizeof(BlkMigDevState));