fixed some crash for NFC.

fixed some crash for NFC.

Change-Id: I6abdd1cd99771a73876ffb5e8d2a9da40d2f19c0
Signed-off-by: jihwan.seo <jihwan.seo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/6309
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
(cherry picked from commit 7a551aee2bb9927f89814f00ca276484a13b8e99)
Reviewed-on: https://gerrit.iotivity.org/gerrit/6317
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Jon A. Cruz <jon@joncruz.org>