radv: Fix file descriptor leak.

radv: Fix file descriptor leak.

Fix defect reported by Coverity Scan.

Resource leak (RESOURCE_LEAK)
leaked_storage: Variable file going out of scope leaks the storage it points to.

Fixes: 57498067540 ("radv: Add Radeon Raytracing Analyzer trace dumping utilities")
Suggested-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18660>