nsswitch: cppcheck: Fix memleakOnRealloc errors
Fixes the following errors
nsswitch/nsstest.c:192: error: memleakOnRealloc: Common realloc mistake: 'buf' nulled but not freed upon failure <--[cppcheck]
nsswitch/nsstest.c:230: error: memleakOnRealloc: Common realloc mistake: 'buf' nulled but not freed upon failure <--[cppcheck]
nsswitch/nsstest.c:269: error: memleakOnRealloc: Common realloc mistake: 'buf' nulled but not freed upon failure <--[cppcheck]
Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Andreas Schneider <asn@samba.org>