Fix data control api.

Fix data control api.

Data control must return SUCCESS on images without smack.

[Issue#]   SSDWSSP-277
[Bug]      security-server_app_give_access returns error on image
           without smack.
[Cause]    On image without smack user passed "" as a client label.
           "" is not acceptable smack label.
[Solution] Function security_server_app_give_access returns SUCCESS
           when smack is turn off.

[Verification] Build. Run all tests. No changes in result should be
               noticed on smack image.

Change-Id: I0c740ecda07e3ed97f1d409c8e597bc3b1f0b773