Fix a possible NULL dereference
Fix a possible NULL dereference

Addressing:
openscap-1.3.5/utils/oscap-tool.c:78:11: warning[-Wanalyzer-possible-null-dereference]: dereference of possibly-NULL 'to'

OpenSCAP/openscap,OpenSCAP/openscap,OpenSCAP/openscap,OpenSCAP/openscap,OpenSCAP/openscap,OpenSCAP/openscap