Plug memory leak in json2cbor
Plug memory leak in json2cbor

In recently introduced code, a pair of temporary buffers is used
to help convert ascii digits to a number; one is a static
allocation but the other is OICMalloc'd, but was not freed.

Change-Id: Iab1e8ce48c20aa6332d375c891f6b38ecb6939e7
Bug: https://jira.iotivity.org/browse/IOT-2863
Signed-off-by: Mats Wichmann <7a5e6f27299d2bbd9d04b59d9e8e4f8eab83d8cb@linux.com>

iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity