Fix badly constructed variables in == operator function

[GF-5570] libpbnjson: Comparing two array-type JValues causes a crash

Open-webOS-DCO-1.0-Signed-off-by: Tapani Mattila <tapani.mattila@lge.com>

Change-Id: Ie11af6484ad02f8aa7a617376ba9c464c6ed7711