Fail more cleanly in mismatched RAM cases

If the number of RAMBlocks was different on the source from the
destination, QEMU would hang waiting for a disconnect on the source
and wouldn't release from that hang until the destination was manually
killed.

Mark the stream as being in error, this causes the destination to die
and the source to carry on.

(It still gets a whole bunch of warnings on the destination, and I've
not managed to complete another migration after the 1st one, still
progress).
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

migration/rdma.c

@@ -3328,6 +3328,7 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
                         "Your QEMU command line parameters are probably "
                         "not identical on both the source and destination.",
                         local->nb_blocks, nb_dest_blocks);
+            rdma->error_state = -EINVAL;
             return -EINVAL;
         }
 
@@ -3343,6 +3344,7 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
                             "vs %" PRIu64, local->block[i].block_name, i,
                             local->block[i].length,
                             rdma->dest_blocks[i].length);
+                rdma->error_state = -EINVAL;
                 return -EINVAL;
             }
             local->block[i].remote_host_addr =