Fix potential memory leak in jobject_create_var()

:Release Notes:
jobject_create_var() should always iterate through all the arguments
even in case of early failure.

:Detailed Notes:

:Testing Performed:
Unit tests.

:QA Notes:

:Issues Addressed:
[ANG-552] pbnjson: jobject_create_var may fail with memory leak

Open-webOS-DCO-1.0-Signed-off-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>

Change-Id: Id7324a081695bfdbe626886ddad159414f9f874b
Reviewed-on: https://g2g.palm.com/4629
Reviewed-by: DCO Verification
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Tested-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Reviewed-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>