blk-dev: hotplug readonly if applicable

If a block based volume is read only, let's make sure we add as a RO
device

Fixes: #1246

Signed-off-by: Eric Ernst <eric.g.ernst@gmail.com>

src/runtime/virtcontainers/container.go

@@ -669,6 +669,7 @@ func (c *Container) createBlockDevices() error {
 				DevType:       "b",
 				Major:         int64(unix.Major(stat.Rdev)),
 				Minor:         int64(unix.Minor(stat.Rdev)),
+				ReadOnly:      m.ReadOnly,
 			}
 			// check whether source can be used as a pmem device
 		} else if di, err = config.PmemDeviceInfo(m.Source, m.Destination); err != nil {