migration: loosen recovery check when load vm

migration: loosen recovery check when load vm

We were checking against -EIO, assuming that it will cover all IO
failures.  But actually it is not.  One example is that in
qemu_loadvm_section_start_full() we can have tons of places that will
return -EINVAL even if the error is caused by IO failures on the
network.

Let's loosen the recovery check logic here to cover all the error cases
happened by removing the explicit check against -EIO.  After all we
won't lose anything here if any other failure happened.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180710091902.28780-3-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>