[IOT-2089] Realloc NULL checks added

[IOT-2089] Realloc NULL checks added

Change-Id: Ie1b99a3815c8126e35576d4c3daa91c73ad66c6d
Signed-off-by: ol.beketov <ol.beketov@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/19663
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Dmitriy Zhuravlev <d.zhuravlev@samsung.com>
Reviewed-by: Andrii Shtompel <a.shtompel@samsung.com>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
Reviewed-by: dongik Lee <dongik.lee@samsung.com>
Reviewed-by: Randeep Singh <randeep.s@samsung.com>