migration/ram: add additional check

If a migration stream is broken, the address and flag reading can return
zero. Thus, an irrelevant flag error will be returned instead of EIO.
It can be fixed by additional check after the reading.

Signed-off-by: Maksim Davydov <davydov-max@yandex-team.ru>
Link: https://lore.kernel.org/r/20240304144203.158477-1-davydov-max@yandex-team.ru
Signed-off-by: Peter Xu <peterx@redhat.com>

migration/ram.c

@@ -4214,6 +4214,12 @@ static int ram_load_precopy(QEMUFile *f)
         i++;
 
         addr = qemu_get_be64(f);
+        ret = qemu_file_get_error(f);
+        if (ret) {
+            error_report("Getting RAM address failed");
+            break;
+        }
+
         flags = addr & ~TARGET_PAGE_MASK;
         addr &= TARGET_PAGE_MASK;