turnip: Fix busy-waiting on syncobjs with OS_TIMEOUT_INFINITE.
I noticed that glmark2's glFinish()es in its offscreen rendering tests under zink were spinning. When we passed -1 as the timeout for drmSyncobjWait(), the kernel would immediately return ETIME.
Fixes: 0a82a26a ("turnip: Porting to common implementation for timeline semaphore")