Fix #14, initialize DirListData with zeros before using

[havencarlson]

Checklist (Please check before submitting)

• [X] I reviewed the Contributing Guide.
• [X] I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution Fix #14, zero out DirListData buffer in FM_ChildDirListFileLoop

Testing performed Unit testing

Expected behavior changes DirListData.EntryName won't have garbage values.

System(s) tested on

• OS: Ubuntu 18.04

Contributor Info - All information REQUIRED for consideration of pull request Haven Carlson - NASA