[media] clang-tidy public/lib/media

Rearranged logic in a dlist remove() method, to satisfy clang-tidy.
Also marked a debug-only local variable as __UNUSED.

This moves garnet/public/lib/media/ to 0 clang-tidy warnings.

Test: build, CQ, "git-file-tidy --all" is clean in public/lib/media

Change-Id: Ie7df57f7267c5502d60a704699f42f0b75ea517e
1 file changed