vmstate: Return error in case of error

If there is an error while loading a field, we should stop reading and
not continue with the rest of fields.  And we should also set an error
in qemu_file.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

vmstate.c

diff --git a/vmstate.c b/vmstate.c
index b5882fa..c996520 100644
--- a/vmstate.c
+++ b/vmstate.c
@@ -98,7 +98,11 @@
                     ret = field->info->get(f, addr, size);
 
                 }
+                if (ret >= 0) {
+                    ret = qemu_file_get_error(f);
+                }
                 if (ret < 0) {
+                    qemu_file_set_error(f, ret);
                     trace_vmstate_load_field_error(field->name, ret);
                     return ret;
                 }