[SSSD] [sssd PR#560][comment] NSS: close files after mmap

[centos-ci]

URL: https://github.com/SSSD/sssd/pull/560
Title: #560: NSS: close files after mmap

centos-ci commented:
"""
Can one of the admins verify this patch?
"""

See the full comment at https://github.com/SSSD/sssd/pull/560#issuecomment-384218286