Update device-mapper-driver.md

Signed-off-by: Johanan Lieberman <johanan.lieberman@gmail.com>

docs/userguide/storagedriver/device-mapper-driver.md

@@ -210,7 +210,7 @@ you how to configure a Docker host to use the `devicemapper` storage driver in
 a `direct-lvm` configuration.
 
 > **Caution:** If you have already run the Docker daemon on your Docker host
-> and have images you want to keep, `push` them Docker Hub or your private
+> and have images you want to keep, `push` them to Docker Hub or your private
 > Docker Trusted Registry before attempting this procedure.
 
 The procedure below will create a logical volume configured as a thin pool to