[SSSD] [sssd PR#916][comment] Fix one coverity issue

[mzidek-rh]

URL: https://github.com/SSSD/sssd/pull/916
Title: #916: Fix one coverity issue

mzidek-rh commented:
"""
Thanks. ACK.
"""

See the full comment at https://github.com/SSSD/sssd/pull/916#issuecomment-550255907