/dev should be constrained in size

There really is no reason why anyone should create content in /dev
other then device nodes.  Limiting it size to the 64 k size limit.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

oci/defaults.go

@@ -91,7 +91,7 @@ func DefaultLinuxSpec() specs.Spec {
 			Destination: "/dev",
 			Type:        "tmpfs",
 			Source:      "tmpfs",
-			Options:     []string{"nosuid", "strictatime", "mode=755"},
+			Options:     []string{"nosuid", "strictatime", "mode=755", "size=65536k"},
 		},
 		{
 			Destination: "/dev/pts",