Update to 11.1.5

There's no functional changes in this update that apply to FreeBSD. Upstream fixed
some issues detected by coverity.

https://github.com/vmware/open-vm-tools/blob/stable-11.1.5/ReleaseNotes.md

PR: 248782
Submitted by: John Wolfe <jwolfe@vmware.com>
Sponsored by: Panzura, Inc